Behaviour Issue After Traumatic Event

[Argent]

I have a 6 month old Papillon that until recently has been very well behaved as far as a puppy goes. There was recently a large fire in the apartment building I live in and, while I did get him out with me, he has developed a few behavioral issues. While most of his chages I was prepared for (eg. barking and fear response to loud alarms) and are showing signs of improvement, there are 2 behaviours that I was not prepared for.
The main thing that changed is he now wants to carry a piece of poop with him EVERYWHERE. If you do not catch him before he comes inside he will bring in some from outside. If left alone he will wither poop inside to carry it around or break into the cat litter box to take cat poop to carry around. He does not try to eat it, only carry it. Then he wants to sleep with it like a child would a stuffed toy.
Should you get the poop away from him, he transitions into the 2nd big issue. If no poop is available and a bedroom door is open he will jump on a bed, urinate and then sleep either in or beside the urine. This does not happen in a pet bed, only on a human bed.
For the first 4months that I had him he has never dispalyed either of these behaviours. I expect that is it related to the stress from the fire. He was cleared by the vet for any health issues from the fire and smoke exposure. They suggested that it may be stress behaviour like puppy PTSD but did not have any real suggestions to fix the issue.
Has anyone come across an issue like this before or have any suggestions on how to resolve this?