Hi anon647698,
I’m only now seeing your post. If the problem is only on the external screen, it’s also possible to scale all programs and content on one screen. Right-click on the desktop (empty screen) > Display Setttings > select the external screen and go to “Scale & Lay-out”. (I’m backtranslating from my Dutch Windows version – it’s Beeldscherminstellingen > Schaal en Lay-out.)
Paulus+Kieviet