AS8 Variometer does not work completely

Hello to all.
I would like to use the AS-8 variometer from the Asobo DG1001 for my own glider project.

So far it can be integrated without problems, except that the two needles in the outer ring do not work.

The only value which is displayed correctly is the altitude.

Can someone give me a hint what this can be?

Thanks for your help
Screenshot 2023-08-21 131457