OK, so…after a bit of experimentation, without having any clue whatsoever as to what I was doing, I have fixed this issue on my machine.
For anyone experiencing this, right-click on Roon, go to properties, and, as @anon47919701 has so helpfully mentioned, mosey on over to the “Compatibility” tab, then click on the “Change high DPI settings” button.
Once in that pop-up menu, make sure “Override high DPI scaling behavior” is checked, and you will see three options in the accompanying drop down menu. Select “System”, re-start Roon, and you should be good to go!
Please do let me know if this works for anyone else who is experiencing this issue, and huge thanks to @anon47919701 for pointing me in the right direction.