No backup import xperiaX -> xperia10

Hello everybody. I have a problem and I can’t get any further. Do you have some ideas what I can do?

Well, I’ve been using an xperiaX for years and have now switched to xperia10. I had some problems with the new device, because I first had to downgrade it and the whole steps from unlock to the installation of SailfishOS were always a bit tricky.

Now Sailfish is running and I want to upload some data backups to the new device.
So far only gpodder has worked without problems. Neither K9-Mail, andOTP nor KeepassDX wanted to import. Whenever I have selected the file to import and confirmed this, a window appears in which it only says
“Open with keepass” (only this time / always)
“use another app” and then there is only “decrypt with OpenKeyChain” and “osmand”. So a real import is not possible for me at this point.

I am grateful for every tip.

thank you very much and best regards
Frank