@0p3ra-us3r i'm having the same problem, opera just deleted all my downloads and some of them were unique and somewhat important for me, instead of clearing just the history like the Windows Version of Opera (in my case Opera GX) would do...
If the devs really would care about happy users then they would probably try to tackle this problem outta the world but no, it's always the "User's Fault" not the Devs...
I get what they're doing...
Programming a mobile Version of a really great Webbrowser but delete the "Clear History Only" function, just to ruin someone's day entirely...
The biggest problem for me in this case is that some of the files in my download folder weren't even placed in there by opera at all, there was a pretty important document in there that i needed to send to my lawyer but no, opera just emptied the entire folder, not just contents from opera's download history, which in my opinion should be definitely illegal...