After upgrading to v11 Beta 2 on Windows 10 21H2 (Build 19044.3803), the Start button on the secondary monitor no longer works when clicked with the mouse. I tried disabled and re-enabling the Multi-Monitor Taskbars, but that did not help. Using the Windows key while the mouse cursor is on the second monitor does work correctly.

I will note that the secondary monitor Taskbar was not showing (even though enabled) after I used RDP from a single monitor (iPad) then unlocked the desktop locally. This worked previously. I had to click Enable All Taskbars to have it show up, so I don't know if that is related.

Sadly the issue corrected itself after restarting the computer. It seemed to only occur directly after running the update.