check screenshot attached it is near impossible to click the icons on the sidebar with a 15 inch 4k display that is designed for active touch pen for drawing, your program is not the only one with this issue, other programs sometimes do it too
Um... There's no screenshot attached, but have you tried to enable hidpi? Either use the checkbox in 3.1.3 or check https://docs.krita.org/KritaFAQ#On_Windows.2C_the_Krita_User_Interface_is_too_small_on_my_HiDPI_screen. to set an environment variable to enable it.
Can you please check my suggestions?
you were right, it was that little checkbox that made all the difference, i would suggest you implement some kind of recognition for 4k resolution screens and have a popup suggest the settings to be changed! :)