i'm assuming you're training JS/1v1? or doing two position OD training?
Two position OD training I could see being slow because of their height, age, OD already being a slow skill (esp. two position which is only like 90% of 1-position IIRC)and potentially elastic effect if it was already their highest skill. JS or 1v1 shouldn't be taking 4 weeks for a pop.
Anyway hopefully you're due for one! maybe even more than 1