I have two thunderbolt LG 4K monitors. After upgrading to beta 3 the startup hangs half way through the progress bar. If I unplug one monitor the system starts up normally. Once up I can plug the second monitor in and all works as expected.
Sequoia Beta 3 (aka 15.2) will not boot with two monitors
Feedback Assistant is the place to report bugs.
I reported this a week ago on Feedback Assistant and no reply!!!!!
We found another problem. If I plug in my second monitor after booting. Now the printer doesn't work. Unplug the second monitor and all good. I have filed feedback for this but still no response.