Creaking noise after catalytic converter replaced

I had the incredible misfortune of having my catalytic converter stolen for a second time last week off of my 2015 Prius. I took it to an auto body shop and had it replaced with an OEM catalytic converter. I’ve been driving it the last few days and I’ve noticed some weird creaking noises when I am accelerating or decelerating under 10 miles an hour with the ICE engine off. It especially happens when accelerating with the electric motor for the first second or so, and also occurs when the car gets stalled on a bump, and I am using the electric motor to try to get over the hump, but the car isn’t moving. It’s more of a creaking noise than a squeaking or squealing noise.

I have tried pushing down on the car over each wheel to see if it is the suspension which doesn’t reproduce the noise. It also doesn’t seem to be coming from the brakes as most of the time the noise occurs when my foot is completely off the brake pedal. I can reproduce the noise when the car is parked and I rock the car. It seems like the noise is coming from where the catalytic converter is seated underneath the car. I also threw the car in neutral and tried to roll it which resulted in a clunking sound which I haven’t noticed before. Does anyone have any thoughts on what could be happening? I am not super mechanically inclined, and don’t know if it is something related to the catalytic converter not being tightened or overtightened, or if it is lingering damage from when the idiots that stole the cat jacked up my car and were messing around. I appreciate anyone’s thoughts, I’ve had a rough week and am about at my wits end!