Comment 6 for bug 1895469

As I wrote in the parallel bug I filed in KDE's tracker (https://bugs.kde.org/show_bug.cgi?id=424606#c2), I've found what may be the root of the bug. Initially I did not report this here because (after finding that KDE Neon, which previously shared the same bug, was now working with KDE Connect) when I tried it in Kubuntu 20.04, it didn't work as it had in KDE Neon. Just now, though, I tried Kubuntu 20.04 again, and it worked as it should for the first time since the upgrade to 20.04 from 18.04.

The upgrade to Plasma 5.20 on Neon a few weeks ago brought a new detail in the log that was not there previously. It mentioned an SSL issue with certificate validation with KDE Connect when I attempted a file transfer, so I did some poking around and found that the version of libssl and openssl in Ubuntu is not the one in any of the distros whose KDE Plasma works well (Fedora 32, Manjaro, OpenSUSE Tumbleweed). The one in Ubuntu was/is 1.1.1f, while the version in each of the distros above was 1.1.1g or 1.1.1h (don't really remember which, only that it was newer than Ubuntu). I did a package search and found that Debian Sid had 1.1.1h in .deb form, and I was able to install that in Kubuntu and Neon without a hitch (openssl and libssl, 1.1.1h, as well as the 32-bit version of libssl 1.1.1h).

Neon began to work after that, while back then Kubuntu 20.04 changed its failure behavior a little, but still was not working. For some reason, it's working now in Kubuntu 20.04 too.