Issues with raspberry pi (no route to host)

Since yesterday I have issues with raspberry pi. I'm running raspberry pi with Debian base and Install nextdns. It was working like charm till yesterday but suddenly my router turns into red light and stops working. I'm using ASUS ZenWiFi AX Mini (XD4) has the latest firmware as well. I attached the log files and please advise me to take appropriate steps. Thank you. Log files 

root@raspberrypi:/home/rk# nextdns log
May 22 02:42:14 raspberrypi systemd[1]: Started NextDNS DNS53 to DoH proxy..
May 22 02:42:14 raspberrypi nextdns[14364]: Starting NextDNS 1.32.2/linux on localhost:53
May 22 02:42:14 raspberrypi nextdns[14364]: Listening on TCP/[::1]:53
May 22 02:42:14 raspberrypi nextdns[14364]: Listening on UDP/127.0.0.1:53
May 22 02:42:14 raspberrypi nextdns[14364]: Listening on TCP/127.0.0.1:53
May 22 02:42:14 raspberrypi nextdns[14364]: Listening on UDP/[::1]:53
May 22 02:44:12 raspberrypi nextdns[14364]: Received signal: terminated
May 22 02:44:12 raspberrypi nextdns[14364]: Stopping NextDNS 1.32.2/linux
May 22 02:44:12 raspberrypi nextdns[14364]: NextDNS 1.32.2/linux stopped
May 22 02:44:12 raspberrypi systemd[1]: Stopping NextDNS DNS53 to DoH proxy....
May 22 02:44:12 raspberrypi systemd[1]: nextdns.service: Succeeded.
May 22 02:44:12 raspberrypi systemd[1]: Stopped NextDNS DNS53 to DoH proxy..
May 22 02:44:13 raspberrypi systemd[1]: Started NextDNS DNS53 to DoH proxy..
May 22 02:44:13 raspberrypi nextdns[14468]: Starting NextDNS 1.32.2/linux on :53
May 22 02:44:13 raspberrypi nextdns[14468]: Listening on TCP/:53
May 22 02:44:13 raspberrypi nextdns[14468]: Starting mDNS discovery
May 22 02:44:13 raspberrypi nextdns[14468]: Listening on UDP/:53
May 22 02:44:18 raspberrypi nextdns[14468]: Setting up router
May 22 02:44:18 raspberrypi nextdns[14468]: Activating
May 22 02:44:38 raspberrypi nextdns[14468]: Received signal: terminated
May 22 02:44:38 raspberrypi nextdns[14468]: Stopping NextDNS 1.32.2/linux
May 22 02:44:38 raspberrypi systemd[1]: Stopping NextDNS DNS53 to DoH proxy....
May 22 02:44:38 raspberrypi nextdns[14468]: Restore router settings
May 22 02:44:38 raspberrypi nextdns[14468]: Deactivating
May 22 02:44:38 raspberrypi nextdns[14468]: NextDNS 1.32.2/linux stopped
May 22 02:44:38 raspberrypi systemd[1]: nextdns.service: Succeeded.
May 22 02:44:38 raspberrypi systemd[1]: Stopped NextDNS DNS53 to DoH proxy..
May 22 02:44:38 raspberrypi systemd[1]: Started NextDNS DNS53 to DoH proxy..
May 22 02:44:39 raspberrypi nextdns[14501]: Starting NextDNS 1.32.2/linux on :53
May 22 02:44:39 raspberrypi nextdns[14501]: Starting mDNS discovery
May 22 02:44:39 raspberrypi nextdns[14501]: Listening on TCP/:53
May 22 02:44:39 raspberrypi nextdns[14501]: Listening on UDP/:53
May 22 02:44:44 raspberrypi nextdns[14501]: Setting up router
May 22 02:44:44 raspberrypi nextdns[14501]: Activating
May 22 02:54:46 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io#45.90.28.0,2a07:a8c0::,45.90.30.0,2a07:a8c1::}: exchange: roundtrip: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:54:46 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 1.debian.pool.ntp.org. (qry=39/res=12) 3069ms : doh resolve: dial tcp 45.90.30.0:443: connect: no route to host
May 22 02:54:46 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 1.debian.pool.ntp.org. (qry=39/res=12) 3070ms : doh resolve: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:54:56 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io}: exchange: roundtrip: dial tcp: lookup dns.nextdns.io on 127.0.0.1:53: read udp 127.0.0.1:46205->127.0.0.1:53: i/o timeout
May 22 02:54:59 raspberrypi nextdns[14501]: Endpoint failed: https://dns1.nextdns.io#45.90.28.0,2a07:a8c0::: roundtrip: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:55:02 raspberrypi nextdns[14501]: Endpoint failed: https://dns2.nextdns.io#45.90.30.0,2a07:a8c1::: roundtrip: dial tcp 45.90.30.0:443: connect: no route to host
May 22 02:55:02 raspberrypi nextdns[14501]: Switching endpoint: https://dns1.nextdns.io#45.90.28.0,2a07:a8c0::
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 2.debian.pool.ntp.org. (qry=39/res=12) 9218ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 11158ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 11158ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 2.debian.pool.ntp.org. (qry=39/res=12) 9219ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 1.debian.pool.ntp.org. (qry=39/res=12) 14227ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 16160ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 16161ms : doh resolve: context deadline exceeded
May 22 02:55:02 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 1.debian.pool.ntp.org. (qry=39/res=12) 14229ms : doh resolve: context deadline exceeded
May 22 02:55:03 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 2.debian.pool.ntp.org. (qry=39/res=12) 5002ms : doh resolve: context deadline exceeded
May 22 02:55:03 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 2.debian.pool.ntp.org. (qry=39/res=12) 5002ms : doh resolve: context deadline exceeded
May 22 02:55:05 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io#45.90.28.0,2a07:a8c0::,45.90.30.0,2a07:a8c1::}: exchange: roundtrip: dial tcp 45.90.30.0:443: connect: no route to host
May 22 02:55:15 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io}: exchange: roundtrip: dial tcp: lookup dns.nextdns.io on 127.0.0.1:53: read udp 127.0.0.1:47170->127.0.0.1:53: i/o timeout
May 22 02:55:18 raspberrypi nextdns[14501]: Endpoint failed: https://dns1.nextdns.io#45.90.28.0,2a07:a8c0::: roundtrip: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:55:21 raspberrypi nextdns[14501]: Endpoint failed: https://dns2.nextdns.io#45.90.30.0,2a07:a8c1::: roundtrip: dial tcp 45.90.30.0:443: connect: no route to host
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 3.debian.pool.ntp.org. (qry=39/res=12) 13406ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 11126ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 16127ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 3.debian.pool.ntp.org. (qry=39/res=12) 13406ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 11126ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 16128ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A 3.debian.pool.ntp.org. (qry=39/res=12) 18412ms : doh resolve: context deadline exceeded
May 22 02:55:21 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA 3.debian.pool.ntp.org. (qry=39/res=12) 18413ms : doh resolve: context deadline exceeded
May 22 02:55:24 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io#45.90.28.0,2a07:a8c0::,45.90.30.0,2a07:a8c1::}: exchange: roundtrip: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:55:34 raspberrypi nextdns[14501]: Endpoint provider failed: &{dns.nextdns.io. https://dns.nextdns.io}: exchange: roundtrip: dial tcp: lookup dns.nextdns.io on 127.0.0.1:53: read udp 127.0.0.1:43845->127.0.0.1:53: i/o timeout
May 22 02:55:37 raspberrypi nextdns[14501]: Endpoint failed: https://dns1.nextdns.io#45.90.28.0,2a07:a8c0::: roundtrip: dial tcp 45.90.28.0:443: connect: no route to host
May 22 02:55:40 raspberrypi nextdns[14501]: Endpoint failed: https://dns2.nextdns.io#45.90.30.0,2a07:a8c1::: roundtrip: dial tcp 45.90.30.0:443: connect: no route to host
May 22 02:55:40 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 11126ms : doh resolve: context deadline exceeded
May 22 02:55:40 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 16126ms : doh resolve: context deadline exceeded
May 22 02:55:40 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP A dns.nextdns.io. (qry=32/res=12) 16127ms : doh resolve: context deadline exceeded
May 22 02:55:40 raspberrypi nextdns[14501]: Query 127.0.0.1 UDP AAAA dns.nextdns.io. (qry=32/res=12) 11127ms : doh resolve: context deadline exceeded