Precision 5750, UP2720Q, shows refresh rate of 59.997Hz

Hello, I recently did clean win 10 install on my Precision 5750 (4K display). After driver updates I noticed two strange things for me - 1. internal monitor of precision 5750 is running on 59.994 Hz refresh rate and 2. my external UP2720Q is running on 59.997 Hz. I found this in Advanced display settings and there is no option for change those Hz. Its strange because before this clean win install I was running both at 60 Hz and there was an option for change the hertz. I thought this might not be problem - but when I for example open Netflix app - it shows titles only in HD (it should automatically show 4K ultra HD) - Ive read that the Netflix require 4k monitor to run at 60 Hz - I was wondering if Netflix can detect that the monitor is running at 59.997 Hz and therefore dont give a 4K playback... Can this be driver related ? Im pretty sure Im up to date both on windows and dell support assistant camp. Thank you very much for any tips how to make monitors run at straight 60 hz , Kells