New Edge ST Thud noise when backing out of parking spot, wheels turned under light load.

I bought a new leftover 2020 ST a few months ago. The day I drove it home I noticed a thud noise ( thought I ran over something) when backing out of a parking spot after stopping for some snacks. As the next few weeks went on myself and my wife would notice it. Finally I figured out it was when backing up and the wheels turned the whole way in either direction under light load. I figured it was something to do with a differential seeing the wheels were turned and going at different speeds, like a clutch pack that was just not operating smoothly. Contacted the dealer and was very specific about what I discovered. They say "bring it in, we think there's an update for the computer". I was a bit confused, but okay. So we take it in, the tech can't verify it, but there's a PCM update so they update it and call it a day. The service advisor wants to go for a ride with me to make sure it's fixed. Well, low and behold, backing out of the parking spot, it does it. He was completely caught off guard as he claimed the description of my concern ( RO written by another advisor) described a transmission thud when backing up... He say's "that's your rear viscous coupler, we've replaced a few in Escapes and Edge's for that exact thing, but they were on back order". Say's he'll call when they are in, probably a month. Well the next week, he calls and says Ford wants them to reprogram the coupler and change rear fluid. Schedule my appointment, make the 1 hour 20 min drive, and come back home via loaner they gave me. Next day, they say it's all good, tech verified it's no longer doing it. Well......it again does it backing out of the dealer lot. So he says they'll order the coupler and call when it's in. 2 weeks later, he calls, I schedule and drop off. It's been 2 full days and nothing. I can see via Ford Pass they put 4 miles on my Edge not long after I dropped it off and nothing since. So my question is, has anyone had this issue and did the viscous coupler resolve it? I couldn't find anything relating to an Edge, but did find a few Escape forums that had them replaced (same part number) but those owners described the thud coming from under the rear cargo area. I feel this is in the front end both by sound and feel, but since it's AWD I could be wrong. I actually wondered if the ST had some sort of front LS transaxle causing the concern, but the dealer is adamant that he's right. Well, the part looks fairly easy to replace so I'm assuming it didn't fix it since it's been 2 full working days. The dealer gives me a loaner which I appreciate, but if it's not fixed, this is 3 times I've had to make time and make the 2 hour 40 minute round trip and it's just getting old. Any one experience this problem?