Please go through this bug, where the live preview is always blocked by the options window.
https://gitlab.com/inkscape/inkscape/-/issues/108
Talking to Ted, the break on Ubuntu/Gnome shell is Gnome shells’ fault. He wants Inkscape to be broken to remind gnome shell developers that they need to fix it.
I am not sure whether to report it to Gnome or here. The last time I tried talking to Gnome about something, they mentioned the support period was over for the version and directed me to talk to my distro
which in this case is Ubuntu 20.04
and related to Inkscape 1.0.2
.
If the team can do anything, it will be very helpful for many 20.04 users.