I have a pair of LG 27UL850-W monitors one is oriented in portrait (if that makes any difference)
They are both using display port to display port connectors and identical monitors
However monitor 1 appears to be about 25% smaller scalling? I have to increase monitor scaling to 125% for it to look similar to the second monitor
Both are set to 3840x2160 60hz within windows and nvidia control pannel.
check the monitors own scaling options.
is it set to stretch to fit? or upscaling off?
also check the nvidia panel for the same options.
when you find em make sure both screens are identically set up
lastly swap the cables over. to make sure its not you using 2 cables with different standards for bandwidth.
Just did a test, if I set them both to 1080p and to scale they look fine, but just not at native? Which would suggest the cables… even though they are identical
well if 1 cable can do the scaling properly and the other cant then i would say yes…
but. you need to check both monitors with both cables.
if it still happens either way round then look at the card.
it might be able to do the resolution but not at the refresh rate you want.
although im pretty sure most should do 60hz on 2 4k screens easily enough regardless of rotation.