Dont use bromide!
Fix a small piece of paper right out of the box. See if it is yellow. If it is, then the support has yellowed and Kodak should know as this should not happen with Endura.
Process a tiny piece in a B&W process and compare with the above, if the above is OK. Both should be white. If not, and the Endura is gray, a layer is fogged somehow by bad keeping or low level light exposure. BTAZ might help but at very low levels. PMT may help as well. Both cause speed loss and may cause crossover.
If the paper passes both of those tests, then the process is somehow at fault as the paper is fog free.