Comment 6 for bug 1846790

https://bugs.documentfoundation.org/show_bug.cgi?id=95336 (why does one always find these *after* typing up a report?) is similar, but
- I get no error message and it definitely chops off the extension as well.
- I get it even with no file chooser dialogues involved, e.g. opening via Nautilus, then just pressing CTRL+S.
- I never had this problem with the Windows version. My naming conventions and workflow haven't changed for >5 years, it's still the same files on the same shares of the same Samba server, the only thing that's changed is that I've switched my desktop from Windows 7 to Ubuntu 18.04 recently.
- Local files are fine for me.

I'd wager the root cause hasn't been addressed and just expresses a bit differently by now.