Hi evtone (we use our real names here, please read Forum Rules),
Welcome to the forum.
This certainly sounds like a case of binder hydration usually called sticky shed syndrome.
Over time, the binder that holds the oxide to the backing changes composition. It usually results in the binder sticking to the tape path (guides, heads) and can make the tape squeal and even stick. Ampex 456 is infamous for this.
The common remedy is tape baking for the tapes and thorough cleaning of the tape path on the machine.
There is much more info about sticky shed in the "Beginners Guide" which can be found in a sticky above the General Forum.