.io .xyz and other less popular TLDs cannot be resolved

I bought a new MacBook Pro 2021 M1, and I can't access URLs ending with .io, .xyz, and other less popular TLDs. The issue does not come from the browser. I tried many browsers and the terminal commands ping and curl. The error message I'm getting depends on which program I'm using to call the URLs. But basically, this is the message I'm getting: "Could not resolve host". The URLs are all valid because I can open them from my phone, which is connected to the same WiFi network as my MacBook. I'm sure the problem concerns the firewall (or DNS?). What can I do to fix this problem? Edit: I used the following command: sudo dscacheutil -flushcache;sudo killall -HUP mDNSResponder It worked for a day and now it stopped working again. I didn't change any DNS or Firewall settings in the meantime.