I know you are probably on top of this, but just in case you haven't seen it yet: Parallels Desktop Pro for Mac version 26.2.2 is not working on macOS 26.4 beta 2. PD itself runs and I can open my Windows 11 for Arm, but it will not start. Then I have to force quit it to get out of it.
Let me know if I can be of further help.
Let me know if I can be of further help.