A/C COMPRESSOR REAR MANIFOLD FITTING

That is a good 'ol STRONG fitting. If it warps it has been severely overtightened or the gasket is crap. I would inspect it with a light, magnifier, and a machined straightedge, and maybe try some fine sandpaper on a glass sheet, or very fine file CAREFULLY Also look for nicks and scrapes on both surfaces.

Also be very certain the bolts are not bottoming

(I don't remember if those are o-ring or flat gasket)