Cryptomator Problems

Greetings all.
I installed cryptomator for my ARM Linux (Linux in an ARM Chromebook, aarch64).
It initially runs but gets stuck at the latter stages of trying to create a container (or open a previously created one).
Also, its shows problems in the location selector dialog box.
These problems were there in the earlier 1.8 version, so I couldn’t use it. I was excited to see a new version (1.9) only to realise the same problems were still there. I have used it in Windows for several years now without issues.
This is the first flatpak app I’ve ever installed but have been really disappointed with it (in addition to the very large data size of its accompanying files). Please help me with relevant pointers if there is still something I have not configured well regarding flatpak or cryptomator itself.
Many thanks.