When I started with the Photon a couple of months ago I had problems with adhesion to the plate, after relevelling I finally tried tweaking the FEP film a little tighter, about 1/8 turn and that did the trick, giving a slightly higher tone when tapped.
I bought a 14w reptile tank heater pad off Ebay, sat the Photon on it in a tray and have room for a bottle of resin also. Keeps the machine reasonably warm. At only 14w I leave it on permanently. My better half has just made me a slip over cover from an old fleece. Only a very occasional problem now which is normally my fault. Don't rely on the auto support placement.
Thanks to everyone who helped me in the past.