Chrome Chromium context menu lag
Solution 1:
The solution is, at least for many, to disable hardware acceleration.
It's under Settings > Advanced > System and it looks like this:
That's usually what fixes this. HA doesn't work with Linux and, last I knew, there was no plan on making it work. I have no idea why it's there in the Linux version, and even less of an idea why it's enabled by default.
This works for all Chromium based browsers, like Vivaldi or Brave.