Stepan Konev

Check the setting in Windows for the view magnification. I have never seen Studio behaving that way...

Thank you Jerzy for your input, 
but I don't think I know what is 'view magnification' in Windows. Could you please elaborate a bit?

Here is a screenshot in German:

Ah! I see. Yes, I have 150% there. But if I put 100%, all the icons and captions will turn too small for me. Does it mean there is no way to balance between good looking Windows and good looking Trados? 

I do not know - I never use this setting. My screens at home are 27" with 2560×1440 points and on the road I use a MS Surface 12" with 2736×1824 - and in any case Windows is set to 100%. When I do trainings, I rescale sometimes to 150% or 175%, but never have encountered what you show.
So try to use View -> Reset window layout. I have too look later, where further view settings for Studio are stored, but have to take care about different things now.

BTW, Windows looks perfect with 100% and not good with 150%, it is all too huge then...

Hi Stepan,

Have you tried this app?

https://appstore.sdl.com/language/app/change-scaling-behaviour/790/ 

Hi Stepan,

Have you tried this app?

https://appstore.sdl.com/language/app/change-scaling-behaviour/790/ 

Hi Nora,
Not yet. Will try it right now. Thank you

The only effect from the app was that it prevented my alternative CAT tool from launching with an error message saying something about wrong syntax in manifest.xml file and SideBySide issues (have no idea what sort of error it is).
After several hours of watching youtube and reading articles, I gave up and was about to reinstall my Windows. As a last resort, I decided to visit that magic app again [to say goodbye] and noticed that its Apply button changed to Undo. I pressed Undo. This removed the SideBySide  error and recovered my alternative CAT tool after reboot. Thank god. Now I came to status quo as before my vain efforts.
Just now I found this thread. Matthew Docherty described a similar, if not same, issue. Unfortunately, I did not find his question before I posted mine... It could save me time.
Nevertheless, thank you Jerzy and Nora for your input.