I wasn't on the ubuntu machine anymore, so i couldn't quickly find the link to the SMB issue, but you're in luck, someone else in this thread already did (he linked it with (in capitals) WHAT THE HECK as link title): https://bugs.launchpad.net/ubuntu/+source/samba/+bug/1697817
And he understood my frustration that such a bug would be open for about 5 years now across multiple major versions. :) . Now i've manually mounted some of the shares, the file manager suddenly also uses a better version of SMB to fetch the shared folders and it suddenly works. But this should take googling & terminal work to just explore a network share from a desktop environment.
Right clicked the .deb package > Open with other application > Open with the Ubuntu software install center app
That's because you're so lucky to not be on a clean 23.10 install, since as i showed in the link i posted, it's not there in a clean 23.10 install for some reason :). I found tons of links saying i should right click, and open it with an application that for some mysterious reason was missing on my ubuntu install :).
I know it's not literally the same, but it's the exact same principle, ubuntu breaking installing deb packages would be equivalent to microsoft breaking installing msi packages. You do understand analogies i hope and realize that it's often impossible to find 100% exact matches when you want to make a comparison.