Menu browsing not working reliable on android app

Installed newest Next-cloud server version 15 ( virtual Machine with Ubuntu server 18 , apache 2 etc.running) and latest android client 3.5.x on Galaxy S5 neo (android 6) and again I’m sad to say , that menu browsing doesn’t work reliable as I mentioned on Github #2947.
Ok, error logs have been cleaned , but problem still there at least for me.
Especially when I click menu entry ‘Foto’ (photos) and then entry ‘Geteilt’ (shares) the app freezes. Maybe it’s a problem of slow speed of my handy (I still work with Samsung Galaxy s5 neo and android 6) , but I tried it on the newer handy S7 (and android 8)too and also here menu browsing wasn’t a stable process.
And moreover the entry ‘Geteilt’ (shares) is always empty no matter if there are shares or not !!
There are no errors shown on server or client - everything should be ok, and desktop client and accessing nextcloud data with webbrowser works fine.
Thanks very much so far for that great project nextcloud , but a small critical note: So much (great) features with nextcloud, but basics won’t work for me (wasn’t that the problem of owncloud ?).
Any ideas ?
Regards, Joe