well, that's very strange.
when I upgraded from p8 to p9 , the Xfce panel might have been confused but the machine was shutting down normally.
I have now installed the p9, and with your valuable help ,I downgraded the core.everything works fine , but the machine won't shut down
I thought about passing the p8 again to do only upgrade to p9 dist ,but not the update of the core kernel, the problem may not be kernel
🤔