Resin Flakes/Failed Prints

This is my first time posting on here so bear with me. I am on my second Form 2 as my first one had a large resin spill and we had it sent it and repaired. On our second one it has been working great! Until this happened…
I was printing with dental model resin, each model had supports, and yet I get a failed print. Each of the models that I were printing fell into the resin tank. The resin in the tank had fragments of cured resin that looked like flakes and I had no clue where this was from. So, I bought a new Resin Tank LT, and new dental model resin and tried to reprint. Yet again, the same thing happens. I’m not sure why this is happening, can someone please help!!?

Here the same thing happened. Replacement of the build platform solved the issue.

Clean the optical path. Galvo mirrors, mirror, and glass.

I will try that. Thank you!