Form3 often does not recognize cartridges!

Hello, my Form3 is increasingly not recognizing the cartridge. It also doesn’t recognize brand new cartridges. I should clean or replace the cartridge sensor in the Form3. Can anyone tell me how to clean this sensor, or whether there is a spare part from formlabs and how to replace it? I would also be happy to provide a link to how to clean or replace it! Many thanks for your help. Regards, Sebastian