Apparently it is something to do with glib2, which the devs are aware of and will tackle.
Rather than downgrading (= risky) I will run Ts via the terminal.
That is the conclusion I have come to.
So, for other users who encounter this problem, the steps to take are:
if you have installed Timeshift, uninstall and install yay -S timeshift-bin
set the Settings as per your preferences
enable a running cron: sudo systemctl enable --now cronie
Timeshift should not start creating snapshots as per your settings. You might need a restart of Endeavour.
If the automatic snapshots still are not done, create them by running Timeshift via the terminal: timeshift --create. To see all the options possible: timeshift --help.
Ya after installing and uninstalling timeshift a few times a few weeks ago I gave up. I thought it was some sort of GUI timeshift bug. I just been using clonezilla since then… Good t know exactly what the problem is now at least. So Timeshift via terminal is fine seems from what you guys are saying …
This kind of package for me would be to restore the system files in case my computer gets messed up irrecoverable.
One has to indicate which files to include, so that is all system files. In Ts the only ones that are excluded are /home/username (which I understand) and / (root - I don’t understand why).
So, the file system files presumable include everything in the highlighted folder below, except home, though I don’t know where root is.
Note that on the Github page there are some 250 open issues, which seems quite a lot to me.
BTW, @s88, @NX-01, Ts is now making snapshots automatically for me, perhaps because I enabled cronie, as told by @dalto.