I just started using GitHub Copilot.
Copilot shows suggestions when I write code, but the autocomplete functionality doesn't work with
I could find out the reason on GitHub Copilot discussion.
The reason was Emmet.
Recently I don't use Emmet heavily so the solution was very simple.
Open settings on VSCode and turn off
Emmet:Trigger Expansion On Tab
In terms of GitHub Copilot, so far so good!