do you have a 2k or 4K resolution monitor - if so this new version may be taking advatage of that by displaying at the native resolution [HDPI - High dpi support] which came at version 18 as I recall

the straight forward way to fix that is to use windows scaling, but that will affect other programs as well - right click desktop, click display settings, scroll to scale and layout: change the size of text apps and other items - you will probably need to restart for this to take full effect