Fedora29 wayland firefox webex screen sharing issue

edit

wayland does have wired api how to get the screen content, next to no program has that adapted yet.

Solution: logout of gnome, choose your user, when you shall enter your password, there is a small icon where you can select your desktop-session, choose "gnome on Xorg" and enter you password correctly! If you make a password mistake, you have to reselect it EVERY TIME until you logged in correctly. Your problem is now fixed :D