My internet acting weird after NextDNS

Hi, I wanted to try NextDNS I am a non-paid user, I configured the DNS via Windows program and on my phone via Wi-Fi dns settings.

On my panel it successfully shows that I am connected to NextDNS then I wanted to do speed test it was a bit slow so I removed the dns from my phone then my internet speed it suddenly dropped from 80-90mbps to 20-25 . I tried on my laptop I can't even connect to internet with NextDNS on. So de-activated and re run speed test it still shows 20-25 ish. And funny enough my whole internet (even my TV, my work laptop, my tablet) slowed down. I tried unistalling NextDNS from eveywhere it did not worked, I tried ipconfig /flushdns renew etc. it did not worked finally I installed Cloudflare WARP it is 80-90mbps again?? But now when devices that is not using Cloudflare WARP  connects to a Wi-Fi my internet is gone for like a minute or two. I tried your troubleshooting tool. Can you guys help me fix this problem?