Was using Ubuntu 20.04 till a couple of days ago where I upgraded to 20.10 to resolve some issues.
Recently I updated from LibreOffice 6 to LO7 as I needed Digital Signature Certificates to work. This issue has been present in LO6 and previous versions for a while for many people. Now in the upgrade process I installed the LO7 appimage to test it, before wiping out my LO6 installation. Digital Signature Certificates work fine in the appimage of LO7 (but not yet on the LO7 install version -- some missing stuff that's in the appimage).
However as LO6 installation still present when I double click on an .odt or .ods file it would open LO6. So I uninstalled it. But the LO7 appimage does not start when double clicking on an Open Document Format file.
Note: I only found on this topic How do I associate a file type with an appimage? that goes back to Ubuntu 16.04 (a really nice and stable LTS). But it's a bit complicated.
Is there a simpler solution?
Cheers
xian