Tiptronic not shifting up
 

Hi,

I just bought a 98 Audi A6 Quattro. The tiptronic on this does not work properly. The automatic transmission works fine. When I shit from D to manual, the display changes from D to 12345. But I cannot up-shift. The down shift DOES work fine.
The usual suggestions I’ve got was to check the magnets. I removed the panel and both magnets are there in place and they didn’t seem to be worn out of power either.. I saw some glues in the panel clips so seemed like someone had already dug in there before me.
What could be causing this. Does anyone have a solution for me? Please help.

Thanks