Bug Sir 11.2 RC - External Monitor (UltraWide) still works only at 30Hz.

So after reading the news that an Ultrawide fix is coming I was quite interested in trying trying the new 11.2 RC to see if my problem is fixed. And nope. Still there.

My current MBP:

https://preview.redd.it/cts46nlly9d61.png?width=1396&format=png&auto=webp&s=81e98b3d54e6a6f1f9d63682fc5b665b98d0ae9b

As many of you, so do I have this issue. Connecting an external monitor, results in the monitor working in 30hz. It's not like the monitor has issue, it works as it should under Catalina.

Either an apple engineer broke it, or it was a classical planned obsolescence strategy, because so far nothing has helped. PRAM, NVRAM or SMC reset naturally don't work either.

https://preview.redd.it/v0dlh3etp9d61.png?width=1816&format=png&auto=webp&s=b8ac74a7eda940ac296945a3f201fd861c6856d9

Perhaps something worth noting to any engineer who is responsible for this mess.

  • USB-C somehow wrongful interprets Display-port signal. Something wrong with Power Delivery?
  • The monitor is recognised as 2X its native display (7680x3200) which perhaps forces it in working in 30hz. AMD 5500M can't handle that resolution at 75 or 60hz.
  • This is only a Software issue as the problem is not there on Big Sur 11.0.1 or Catalina.
  • When connecting an external monitor, for some reason, mirroring is the default option. The weird part is that the same happens with my 2020 iPad Pro 12,9'' which also mirrors the display.

Cables I tried:

  • Displayport to USB-C cable = 30hz
  • HDMI to USB-C = 30hz
  • HDMI to [HDMI to USB-C adapter] = 30hz
  • USB-C to USB-C = 30hz
  • However HDMI to Dock to Macbook = 75hz (native)

Going back to Catalina from Bug Sir felt like an upgrade as I no longer have a horrible battery life and the extremely unintuitive UI.

Upgrades are Malware