This post is very interesting. We have a GSD from the rescue, she is almost 2 years old. Spent most her life either being strapped down (hip replacement, 3 months) in the rescue or pound. We may be experiencing the same issue.
She turned out to be a fence jumper with aggression so we had to kennel her for about 6 weeks. The kennel is attaches to a laundry/utility room (5'x5') and the kennel is 5'x12'.
When we would return home from work, I would go into the laundry room, spend about 5 minutes sitting there (no touch no eye contact) until she calmed down. After that point I would let her into the house and into the yard.
Well one time my wife walked straight to the laundry room and let her out immediately and there were pee drops all over the kitchen.
She likes one of my neighbors alot. This neighbor, Andrea, rescued her 3 times when she jumped over our fence on different occasions. I once saw Andrea while walking the dog. We ran over to say hello. Her tail was spinning like a propellar and of course rivulets of pee all over the street.
My 2 cents. Try making sure that she is very calm before allowing her in the house.
BTW fence has been modded and no more kennel, thank the lord, buddha, allah, etc.