Happy to assist.
Some internet providers enable DNS rebinding protection on their DNS servers. Your provider may have made the decision to adopt it recently which is why it changed overnight.
Personally, I find Google DNS or Cloudflare DNS quicker than my internet provider’s service and have always used that instead.
You may also want to consider enabling DNS Privacy Protocol on your router so that your DNS queries between the router and Google DNS can’t be snooped on or spoofed.
