I am having the same issue with my Mac Studio Ultra. My current setup is 2 x LG 27UL850-W 4K monitors and 1 x Wacom Cintiq Pro 24. I have had two LG monitors plugged into OWC Thunderbolt 4 Hub, and Cintiq Pro connected directly to the Studio. To isolate the issue, I plugged in one of the LG monitors directly to the Studio and disconnected everything, and I was still having the problem. 2nd day I connected the Wacom monitor, and I did not have the same issue.