Can somebody that uses vlc tell me what happens in situation described in the title?
On mine, when i start vlc after exiting in fullscreen mode, it forgets the window size that i had before going to fullscreen mode.
Try this, https://superuser.com/a/368759/699547
Open any video and resize the VLC view screen to whatever size you want. Drag the corners and then go up to the Menu-bar at the top... Tools>Preferences>Interface>UNCHECK "Resize interface to video size" and click save.
Close your video and reopen to verify the correct setup.
Its a two-step process. Drag and size your viewing screen, then UNCHECK the "Resize Interface to video size" and SAVE.
Strictly speaking this question is off-topic for EOS stack overflow, however I've tried to answer it anyway.