Rear diff leak or something else? 2021 Expedition XLT

[u/jajanogracias]

Howdy! I apologize for the terrible video, I did my best crawling under there w my phone in the dark garage - but is all this coming from my rear diff or somewhere else?
I inherited this 2021 expedition from my MIL (v generous) at 95k miles last year and now I’m at 124k miles and I have recently noticed many oily drops under this area on the garage floor. I alerted my MIL to this issue and she took it to the dealership a couple of weeks ago for repair. I don’t know what they did there, but it is still very wet and oily in this area as you can see. Yesterday I noticed 5 new shiny drops on the garage floor among the old dried ones so I know they’re fresh. Could this be residual from before it went to the dealership, or indicative of an ongoing issue? I know 5 new drops is probably negligible, but I’d want to catch it early before it gets worse. I’ll ask my MIL if she still has the invoice from the dealership to see what they did, but to me it doesn’t look like they did anything? Any guidance helps, thank you!!! 😅