Network error since the macOS Catalina update No internet, "ERR_INTERNET_DISCONNECTED" error in chrome since the macOS Catalina update. 

I tried,


resetting the router
reconnecting to the wifi it in safe mode
diagnostics report


I tried it in Safari and Chrome a few hours ago and it didn't work in both of them. Now, it isn't working in Chrome but surprisingly it is working in Safari. 

PS - Again it stopped working :( 
I can open Stack Exchange in Chrome but not other sites. What is happening?
It's a DNS resolver problem inside the macOS. It's not picking up the DNS servers provided by the router or inputted manually in the 
"network settings". The actual Internet connection is still there - you can confirm through running nslookup apple.com 8.8.8.8 through the Terminal.

The only way to solve this as of now is to reboot the Mac. Killing the mDNSResponder doesn't help.

I would also recommend contacting Apple Support through the chat, explain them this problem (and the solution). They will schedule a call with second line of support. You explain them the problem again and they will send a note to developers. I already sent my report in - more reports should expedite them releasing a fix.