Resin printer issue-a quarter of the print is fouled half way through the print

[dibble]

Tried to put as much description in the title, but it was getting out of hand. See the pic of the "completed" print still in the printer for detail.

In short, printing a resin model and 1/4 of the model got fouled well in to the print, then resumed as normal. It looks like the supports just stopped adhering on part of the screen, then the model resumed?? I've never seen anything like it. Any ideas what caused it? I've printed this same .STL at smaller scale (see other pic), so the .STL is fine. It's the first attempt at printing the file this large.