Desktop on Zorin 17.1 won't shut down

Hello world:-)

I am running a Lenovo B40-30 AIO Desktop on Zorin 17 now.

Everything runs pretty well. I am still fighting with the right encryption options, but so far still using my NTFS bitlocker partitions, which now work excellent on 17.1.

The issue I have is, that the system does not switch off completely, when I power off - the fan is still running, until I press the button long to power off.

I read in the forum, that someone had this issue on hos laptop with OS 16, but that seems to be a general issue with the power or energy management.

Any ideas out there?

thanks in advance!