The update from Fedora 30 to Fedora 31 was a disaster. First, the update manager has downloaded 4GB of data from the Internet without telling the progress or the reason why so much packages are needed. Secondly, after the installation the Lyx software was broken.
In the first trial, Lyx had problems with background flickering. A first fix to the problem has introduced a new problem which is the malfunction of copy&paste. Right now, the Lyx software isn’t working at all. So the advice is, that if somebody is using Fedora 30 the better idea is to wait until Fedora 32 is published and not update to early.
The only advantage of the update was, that the home folder wasn’t removed. That means, all the data are available. But it seems, that the maintainer are not sure if this is working in every case. So they are recommending more than 3 times to backup all the data. Perhaps with the reason, that in the past users have lost their home folder?
X11 works
The problems with the Lyx software can be fixed by switching back from Wayland to the X11 environment. This can be activated in the login menu. The settings button allows the user to decide between Gnome under wayland, gnome classic under X11 and gnome under x11. If he selects the X11 version, Lyx will run normal. That means, the graphics are display normal and the copy&paste function is working. It seems, that the problem is located within the wayland display server.