When I try to share my screen in google meet, I just only can share a tab, but the share entire screen option or share a window option is not available. Currently I am using Ubuntu OS 22.04 LTS.
When trying Google Chrome at the same setup the screen sharing works well for window and entire screen. @Alice2095 asked in the similar topic if it works in the private tab, I tried this, but same issue.
I found the solution thanks to another topic about Progressive Web Apps not available as app in Ubuntu in Brave. Someone wrote it is because Brave was installed by Snap. I deleted the Ubuntu snap version because of that and installed it by apt as instructed by https://brave.com/linux/ . Now both window/screen sharing and PWA available by app in Ubuntu is working well.
I am not sure if it is a limitation of snap. Possibly someone from the Brave team can look into it as the Brave snap version at https://snapcraft.io/brave is maintained by Brave itself.