It appears to be reticulation to me, too. There is nothing you can do about it. The gelatin layer is already physically damaged.(posted 8236 days ago)AGFA's APX films are very susceptible to this damage if it is exposed to high temperature during any stage of wet processing, including washing and drying. A sharp fluctuation of temperature is also a danger. Pay attention so that the washing temperature never exceeds 27C or so. I recommend that APX films as well as Kodak's PX and TX be processed at regular 20C and pay extra attention if the processing temp has to go higher or drying cabinet uses temperature higher than room temperature.
Ilford films and T-MAX series are much more robust against this kind of damage, at least when I tested them last time.