Phantom layer spots on release film occurring

Hi, I have two Halot One Plus printers that have been working very well for year until lately. In the last month or so I have been noticing spotty single layers of resin building up with every print on the release film. The spotty layers, are thin, like a single layer of .05mm and are not located in the area of the item is being printed. In-between each print, I check for these phantom layers and sure enough they show up. I clean them off, then do another print. These printers never used to do that.
The release film has been replaced and the printers build plate leveled. I am using the HALOT BOX version 3.5.6, which I like and have been using for a year. The printers are at version 2.303.1 firmware.
I use these printers on a daily basis.
Any suggestions of the possible issue?

Hi daniel it could be the slicer, i recommend trying different slicer.