Could be, but the print core cools down a little bit when not in use, to avoid such things. You could try to enable the prime tower, but I am not sure if it really helps.   I assume that your humidity is too high in the room, so you start your print and everything is fine, but after some hours the PVA gets too wet. You should really get a dry box or in the meantime, take an airtight plastic bag, put some silica gel packs inside and open it just a 1-2 cm to get the filament out. Put the