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decisions

macrumors regular
Original poster
Sep 30, 2019
221
583
MBP 2018 i7 macOS Big Sur 11.5.1
HD EliteDisplay s270n

Hey everyone,

I got this monitor about 6 months ago and have been using it with this laptop ever since. All of a sudden, yesterday, I started to notice that animations on macOS looked choppy and soon I realized that my monitor had been switched to 30Hz mode. The problem is that the optimal mode which I've been using for months, 3840x2160 60Hz, is no longer selectable for use with this Mac. If I download EasyRes the setting is just gone. The highest 60Hz setting is 1440p. However, in the monitor's internal menu, the optimal mode is still listed correctly.

Any idea what could have happened here? I guess some Big Sur update just broke this? I really have no idea as it didn't seem to start happening just after an update or anything like that. I didn't change anything with my setup (I connect the MBP to the monitor via a single USB-C cable for power/display and have tried unplugging this several times at both ends).

So my 4K monitor just got downgraded to a 2K. Thanks for any help.
 
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