If you're running Ubuntu Mate and your Zoom suddenly has huge buttons, it might assume you're using a very High DPI display. While this is usually a good idea, the heuristic determining whether to enable this HiDPI mode or not does not work perfectly with Ubuntu Mate and multiple displays.
Unfortunately, this setting is not exposed in the GUI, you'll have to change the config file.
First, make sure zoom is closed completely, i.e. there should not be a zoom icon in the panel next to the clock.
Open ~/.config/zoomus.conf
and search for autoScale
. Make sure it's set to false
.
scaleFactor
parameter to 1
.scaleFactor
to 2
.When you re-open zoom, buttons should have the desired size.