Hi pump_studio,
yes, this is correct. 3ds max2016 UI does not support 4K monitor.
You might try deleting the 3dsmax.ini
Close 3ds Max 2017; copy You 3dsMax.ini to another folder, and delete it from the 3dsMax folder.
Restart 3dsMax.
reference:
https://youtu.be/_Vu_oySZF34
Paride