Thank you for your fast reply!
My native Resolution is 3840 x 2160. My GPU is NVIDIA GTX 980 Ti.
The provided walk around with checking “turn off scaling for high DPI values” worked flawlessly.
I fear that many not so computer firm users won’t find this solution, so a future patch would be wonderful. Maybe an option to make the fonts and GUI elements somewhat bigger to prevent me from needing glasses when using the native resolution in Train Fever in future patches?
I love this game and the support and ambition of it’s creators, thank you very much for your time and help!