Screen flashing when hoovering over menus

[Moshe Caspi]

It happens in Firefox and Thunderbird, only on Hebrew (RTL) menus, and on bookmarks toolbar folders (Firefox), when hoovering over them. The first time will be ok but flashings start from the second attempt. See attached videos.

ProblemType: Bug
DistroRelease: Ubuntu 22.04
Package: mutter 42.9-0ubuntu7.1
ProcVersionSignature: Ubuntu 5.15.0-106.116-generic 5.15.149
Uname: Linux 5.15.0-106-generic x86_64
ApportVersion: 2.20.11-0ubuntu82.5
Architecture: amd64
CasperMD5CheckResult: unknown
CurrentDesktop: ubuntu:GNOME
Date: Fri May 10 10:51:42 2024
InstallationDate: Installed on 2019-04-03 (1863 days ago)
InstallationMedia: Ubuntu 18.04.1 LTS "Bionic Beaver" - Release amd64 (20180725)
ProcEnviron:
 LANGUAGE=en_IL:en
 PATH=(custom, no user)
 XDG_RUNTIME_DIR=<set>
 LANG=en_IL
 SHELL=/bin/bash
RebootRequiredPkgs: Error: path contained symlinks.
SourcePackage: mutter
UpgradeStatus: Upgraded to jammy on 2022-08-12 (637 days ago)

[Moshe Caspi (mcaspi12)]

It looks like it's happening only when logging in "Ubuntu", and not in "Ubuntu on X11".

[Moshe Caspi (mcaspi12)]

In Firefox, when changing the Language setting to English, the problem is solved.