How to Resize VLC Media Player to same Window Size of your last video || OS Authority
Select Tools ⇨ Preferences ⇨ Interface then uncheck the box Resize interface to video size and the box Integrate video in interface, restart.
Start movie now, if you notice there should be 2 windows the main and the video window in 2 separate windows now.
Go back Select Tools ⇨ Preferences ⇨ Interface then check Integrate video in interface Finally, restart VLC.
The video windows return normal to its default inside the main window now the movie stay in the location you want, resize as you like, close the movie open and notice stays in the size you have choosen.
I don’t know how it this but after trying that’s how it works for me.
Other option I have found is: