PNG colors in source AI file get inverted after saving to pdf
This issue popped up about 3-4 weeks ago. PNGs (not all of them) in my source AI file get color inverted / messed up (see below).
It only seems to only happen after I export or "save a copy" as a pdf. It doesn't happen immediately, only once I have closed the AI file and reopened it, the PNGs in the reopened file have now been color-borked.
Also, it doesn't happen to all PNGs, just a few. Any ideas?

