Got an Intel Nuc with libreelec connected to a Denon AVR-1912 which is connected using HDMI. The NUC is always turned on and sometimes when I start the tv and the recciver the output of the gui is set to 50hz, which results in brighter colors and not as smooth as it should be. Not quite sure how to replicate the "error" but guessing that it's when I turn the tv and recciver of when my IPTV (25fps) is running. Although it doesn't happen every time... If I reboot it's back to 60hz again.
But to the question, is it possible to force the gui to only output 60hz?