Being blocked by NextDNS

Starting Thursday August 28th around 6pm EDT, NextDNS stopped responding. 
Knowing that when Internet goes down it might be not down, but it can DNS, I started troubleshooting on my end. I can ping cloudflare, but can't ping 45.90.28.0 or 45.90.30.0 (or any IPs in that range). I can't connect to port 853 of either. nextdns.io sometimes won't load, test.nextdns.io won't respond, etc.

trace route suggest that packet does not reach 45.90.28.0 and 45.90.30.0. 

So I switched to cloudlfare's DNS. Everything working (except NextDNS). Several hours later, I see that nextdns servers started to respond. I re-enabled nextdns on my firewall only to see that few minutes later I was blocked again: no traffic can reach nextdns resolvers. I see packets leave my firewall, but no acks received from the other end. 

nextdns.io/diag never finishes to the point it can submit the report when I'm being blocked. when everything is working -- it just finishes fine, like nothing happens. so I can't capture and submit report when it doesn't work.

For example, right now I've been blocked again and diag struggles to do the work, timeouts seems to high... but 5 minutes later ( it's sometimes 5, sometimes 30 minutes, and sometimes 2 hours)

Fetching PoP name for ultra low latency primary IPv4 (ipv4.dns1.nextdns.io)
Fetch error: Get "https://dns.nextdns.io/info": dial tcp 162.220.223.23:443: connect: connection timed out

Please help. 

Upd 25 min later: https://nextdns.io/diag/3de629e0-85be-11f0-8625-474f7bd21362