Upgraded my M1 Mac mini from MacOS Tahoe 26 Beta to Beta 2. Prior to the update I had no problem connecting to the Max mini from my MacBook Pro M2 running Now, attempting to connect to the Mac mini from a MacBook Pro M2 running Sequoia 15.5. After the update, I can enter my password, but then I am disconnected with the error "This Mac was unable to start a High Performance connection to the Mac mini" and to "change the screen sharing type to standard and try again"
Connecting via a "Standard" connection showed that the Window Server failed.