What causes this on the FEP?  

What causes this on the FEP?

Lately I have has issues with small prints missing part of the print.

After each print, I usually empty the basin and filter the resin, before checking the FEP: Either there was nothing on the FEP or at the most a small cured resin disk that was easy to remove. The reason seemed to be too few supports on a pad, with the FEP pulling the first layer that as supposed to attach to the supports clean off the supports.

Then yesterday I started another print, again with half a dozen smaller objects to print. This time I manually added a lot of supports, hoping to prevent the previous issues. I also lowered the cure per subsequent layer time from 9 to 8 seconds per layer (and 95 seconds for first layers on the pad).

Much to my surprise, most of the print seemed to have gone well, with some pieces missing once again. When draining the tank, I saw this (attached image):

What can cause much of the surface of the FEP to suddenly (in one print) become covered in a layer of cured resin, with a larger disk being several layers thick?

Is the LCD-screen already failing or is this caused by something else?

I'm nowhere near the advertised "500 hours" lifespan mark of an LCD, having maybe printed half a litre of resin in total with this LCD.