Mouse cursor stuck in screencast recording videos

As commented in #1208 (closed):

• #1208 (comment 1204389)
• #1208 (comment 1212862)

There seems to be a regression with screen recording under X11: the mouse is stuck at the top left corner. It can be reproduced with both the built-in GNOME recording tool (CTRL + ALT + SHIFT + R) and Kooha.

Using:

• Fedora 34 Workstation (fully upgraded)
• GNOME 40.4
• X11

Here is an example while interacting with the mouse (select text, move window...):

Screencast_from_2021-10-12_18_37_51