Prints have another high as in the file

Hello community, i have a Form2. Since recently, the prints are faulty. I have for example: a flat rectangle with a pattern printed on the front. This has a high of 6mm in the original. If I print this with a support construction, only a few parts of the motif are visible, the other ones disappear. If I print it directly on the platform (without support construction) 1mm height is missing. Does anyone know what this is? The Z fine adjustment was not done.
Thanks

When was the last time you cleaned your printer’s mirrors? How old is the resin tank?