Power Liftgate/Lift Gate Popping/Knocking and OEM vs Third Party Motor Oil [FXT 2018]

Sorry for synonyms in title, for easier searching.
Also sorry for new thread, I tried searching to find it, but I only found one on the Outback forum.

Like this outback owner, my 2018 Forester XT has a popping/knocking sound coming from (what I believe) is the left power rear gate motor.
It's not as bad as the following video,

Thread from subaruoutback.org: subaruoutback [dot] org/forums/138-gen-5-2015-2019/312649-power-lift-gate-knocking-when-raising.html

Video posted by that Outback owner: youtube [dot] com/watch?v=wsrQCVp0BFw

First post, so not allowed to post links yet.

As well, I went to the Subaru dealer for an oil change. Instead of putting in the Subaru Synthetic Motor Oil SAE 5W-30 (gold bottle and blue label), they put in Mobil1 synthetic (silver bottle)
Is there a major difference between the two? There does not seem to be consensus on differences of OEM vs third party motor oil. Is the Subaru synthetic still made of mineral oil and not 'truly' synthetic? Not sure about this point, hope someone could clear it up definitively.