Hello and many thanks for all your usefull comments.
You may have read in the press that here in Spain we actually have a strong winter with a lot of snow really and arctic temperatures (coldest point of Spain on saturday was - 35,9° !!!).
In my workshop I have today - 4 degrees. Now you can say: Stop turning and protect your fingers, but woodturning is like a drug meanwhile jajaja. Specially the holm oak or holly oak whit it´s beautiful texture and grain, which grows in abundance here, is my favorite. Very hard wood really, so I need a lot of sharpening
But I managed the problem, just took of the leatherwheel and gently treated the rubber with 150 grid sandpaper a little bit and it works perfectly.
In my case the pages 161-163 of the handbook has been very usefull. But the best was the service of the german distributor Tixit, who called me and explained me the mentioned solution. Fabulous service. The support team from Tormek itself didn't answer my request.
So again, many thanks to all of you and happy 2021, which only can be better