@arubislander I have no vim at my drawer, and never had. Have only 'Terminal'. Do you mean this?

@arubislander Thank you very much for the hint!
I'm also on stable channel and with 'Settings/Updates' I updated EVERYTHING including all apps to the latest version and then rebooted the device twice.
After this it was possible to install a Libertine container, but it needed full an hour to download and install.
But by giving it time and waiting patiently it worked and now I have an empty but working container, will say container starts and some settings are available but no applications yet installed.

Volla, after installing the last OTA update:
Tried to install a new Libertine container, both container name and password empty.
Result: endless spinning circle, nothing will be installed. Grey bar with "Installing 'Focal Fossa" is displayed. I waited 2 hours.
After a reboot spinning wheel persists and no way to stop/abort.

Then I tried to install a container with a name and a password but it also didn't work.

Edit: found a way to stop by swipe the grey bar to right and select trash.

I used a Volla for more than 2 years with another OS -> no ghost touches
Then I flashed the same phone to UBT -> ghost touches occured sometimes, 2-3 times per day.
Then I updated UBT with the built-in updater -> no more ghost touches, phone works now fine.
So I think it was NOT hardware related but an old software problem, but it seems to be solved by the last OTA update. But not on a fresh flashed system ftom UBports Installer!

So after my experience, everyone who still has this problem, simply try to update to the latest OTA update version.

Hi!
To the initial question: Yes, I used SFOS for 4 years and now after a failed flashing procedure I installed UBT on Volla (GS290) for curiosity and for way of variety.