A32nx approach issues

If anyone here is using a32nx - have you recently been unable to maintain a stable altitude below fl10? Auto pilot seems to obey my command to descend to a certain level but once it’s reached that point, it starts trying to climb uncommanded

I had this problem today during open descent. I don’t know what happened there and i switched off the AP and flown manually to my altitude and get the AP online again. Still had that problem but I got it work again somehow.
Don’t ask me how, but I guess it’s a bug in the actual dev.