@crmrhm: A bit more experimenting…I get ‘Invalid Argument’ reported in the VLC logs when attempting to play content from my Windows 10 shares (where no password is explicitly set). If I first start VLC from a terminal with the following…
vlc --smb-user "user" --smb-pwd "pwd"
(* In my case any username/password combo works as my Windows shares are configured for “Everyone” access for test purposes)
…then if I subsequently play a video by clicking on a (Windows share) file via Dolphin, VLC will play it happily. It seems to me that it is as a direct consequence of the way VLC attempts to access the media (depending on whether the media requires authentication or not perhaps).
I got some insight into this by following this thread…
https://code.videolan.org/videolan/vlc/-/issues/22151
It will be interesting to see if this helps with your situation.