I have had similar problems with Mobil 1 grease. I also just simply did not like the consistency of the stuff, not sure how to describe it, but I just didn't like it.
I am an open-minded AmsOil fan. I don't believe AmsOil is the only oil that will do the job, but it is my go-to for extended drain interval applications. I also love their gear lubes, greases, and tranny fluids.
That being said, I have not had good luck with AmsOil's S2K grease. No component failures, I just didn't think it was tacky enough and tended to sling out of my wheel bearings rather than stay in the rollers. I now use nothing but AmsOil's Multi-Purpose #2 grease. Stuff stays where I put it, without being overly tacky, and performs very well.
Just my two, alright, maybe three cents, and my experience may be unique.