I have had a similar scaling issue using the VLC from snap. Seems the snap version creates a container that doesn’t use the system font configuration. Probably a bug.
Using the Ubuntu package solved the problem for me.
sudo apt-get install vlc
Here is the Ubuntu-Budgie-Forum thread that discusses the problem.
User Codic recommends installing qt5ct package, what didn’t work for me, but might be able to help you. I am copying the relevant part.
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"Install the qt5ct package from the repos, then open “Qt5 Settings” from the menu.
There, under the fonts tab, change your font. If you run into a snag,
check Can’t use Qt5ct to change global application style to kvantum
first. "
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