Just to follow up.. I sent a quick email to NGC and also to the seller of that coin and they both said similar thing.. that grades are determined by consensus.. Seller said coin is not perfect and many times they just eye it. NGC said they could look at it again etc... Seller of coin offered to exchange or refund... was willing to do exchange but ebay system was giving me problems with exchange option so it was easier to submit for refund so did that. I received other coin by PCGS and it looks superb even under 40x loupe. Reading around it seems both NGC and PCGS are pretty equivalent - one is not really better than the other in general - so I guess I just had some bad luck with that first coin with NGC.
As an aside, I ordered a PCGS first strike philadelphia emergency release 2020 MS70 coin.. apparently there were only 240,000 of these minted at philadelphia mint for a few weeks.. temp. used because of covid issues I think at west point. This is supposed to be second rarest release (third but one is not counted). Am thinking about getting an NGC one as well. I guess it could still amount to nothing, lol, but seems to my novice eyes worth taking a little chance on.