Asus does have a factory in Viet Nam. I don't want to further worry you but that is where the Z690 motherboards that were failing and in some cases catching on fire due to a capacitor being installed backward came from. Any company can have a bad run. What concerned me about this one is that several people who work in circuit board assembly said that this mistake should NEVER have gotten past the automated QC checks that are standard practice for a product like a mobo. Apparently, each completed board is optically compared to a high-resolution reference photo and that process should have caught this error before the boards made it out of the factory. They were amazed that boards got released with this assembly error. Asus dodged the issue until it started showing up in the Trade Rags.
I should clarify that I don't own one of these boards so was not affected by this problem. I did go check where my Crosshair VIII Dark Hero and TUF 3080 OC (10G) were manufactured and was relieved to see that they were manufactured in Taiwan. I think Asus builds and ships from Viet Nam to get around import tariffs on products made in China. As for your GPU, I would not be concerned that it's not a real Asus GPU but I would inspect it and test it extensively RIGHT NOW.
As for New Egg - since they were bought by a Chinese company, their customer support has nosedived. Check out the New Egg Reddit for endless nightmare posts about New Egg delivery problems, shipping used and known defective merchandise, and refusing to accept returns or issuing refunds. Gamers Nexus even flew out and met with New Egg executives and called them out on this. Promises to improve were made but IIRC, when they checked back, everyone they met with was no longer there. I refuse to buy from New Egg anymore under any circumstances, which is a shame because I used to buy from them a lot. If I were you, I would install and test that GPU before any more time goes by. Don't wait. DO IT NOW. Good luck!