Are you printing with the DF resin for this? If so it sounds like the adhesion to the build plate has reduced. The small parts will not require much adhesion to work well, but the larger print has quite a lot of surface area and as such adhesion issues will be noticeable.
Some questions / points for you:
1: What does the pdms layer look like when you look through it? Often its more clouded in the middle, where most people tend to locate prints. The clouding limits the amount of UV energy getting through for the cure. That will reduce the adhesion
2: Has anything changed with the resin?
3: The increase in temperature is normally a positive thing in terms of adhesion, it lowers the viscosity of the resin which in turn increases the reactivity of the resin - which gives greater adhesion to the build plate and less suction as the build plate lifts.
4: Have you done the Formlabs optics print test to check the optics? Dust / dirt on the mirrors can have a very adverse affect on adhesion in different areas of the build plate.
If you don’t have the test file, this thread has a link to it (in Fantasy2 post) Clear Resin - Print failure