CVT transmission problem

Hello, I have a Nissan Micra k11 Bj. 1995 with a CVT transmission and the famous magnetic powder coupling. I have some idea of cars, only unfortunately none of AT transmissions at all the following problem: In slippery rides especially when I drive slowly into a driveway (about 10-20 km/h) a squeaking can be heard, which sounds almost as if a V-belt would squeak. The squeaking becomes more when everything is at operating temperature. If the squeaking occurs and I do a little more The car is only recently in my possession and was previously driven by an older lady who spent about 19 years each year doing something more than 2000 km. Maybe a transmission expert is on the way or someone who had a case like that. Oh yes. Gear oil has changed. Error memory is empty. Thank you in advance.