I'm forwarding a bug originally reported by a Debian user, see here for details: https://bugs.debian.org/984498
Here's a quick summary:
- Writing text is very slow in apps that use WebKitGTK: ~300ms to have letter to appear in a mail reply and about 40% of one CPU core usage on Gen6 i7.
- Display: 4k/60hz screen running on Nvidia GTX 1660 SUPER with proprietary drivers
- This problem does not happen at lower resolutions (1366x768)
- The problem appeared suddenly around the time he upgraded to GNOME 3.38.0
The problem happens with versions 2.30.x and 2.31.90