I've found a bit of a hack-y workaround in the meantime. I have an Elgato HD60X Capture Card. If I place this between my MBP and the 2nd Monitor, it gets detected and everything seems to work as expected.It's quite a strange issue. I'm by no means a ...

Interesting - I wonder why Hopefully Apple can figure it out on their side - because that's really my only option now.

 I doubt it's an issue with the TB5 bus in the M4 Pro, as i'm also experiencing the issue on an M2 Pro which is TB4. With your M1 Pro, does it only work when using the TB5 dock? or were you also able to get it working using say HDMI and USB-C? I spen...

I'm experiencing the exact same issue - with a 16" M4 Pro MacBook Pro and also a 14" M2 Pro MacBook Pro. I've tried:Both monitors connected to a Thunderbolt 4 Dock (Corsair TBT200)  using USB-C to HDMI Cables. Only 1 monitor will display at a time. D...