Were you able to successfully receive a message/file sent to self from Conversations on another client? ie. another Convesations? or any other OMEMO compatible XMPP client?

I'm asking about that, bacause main reason why people cannot see their messages are actually releated to the fact that those messages are not encrypted for particular device.

As for being listed in "From unknown" section, the behavior is correct. If the sender of a message is not in your contacts list (roster) then it listed in "From unknown" section.

Were you able to successfully receive a message/file sent to self from Conversations on another client? ie. another Convesations? or any other OMEMO compatible XMPP client?

I will check this. I have a Gnome client somewhere that I sometimes use.

As for being listed in "From unknown" section, the behavior is correct. If the sender of a message is not in your contacts list (roster) then it listed in "From unknown" section.

Ah, I see. I could not find a way to add a contact in the "From unknown" section to my contacts list (only to block them). Now that I have added myself from the real "Contacts" window, I show up as expected.

Sorry it took so long. I've now tried it with Conversations -> Gajim. It worked. Then I discovered that the file was also available on Beagle (though not past ones), even though I still got that OMEMO fish from the original screenshot.