White label stuff comes with options.
Just because the case is different or the pcb color is different means nothing, companies do this all the time. Small housing changes, somewhat major housing changes, pots, knobs, are all pretty easily changed for a small fee. Electronics in particular have been getting swapped lately as companies have had to scramble to replace harder to get parts due to shortages (Asus in particular has had a hard time with it).
As for the false positive, that was my initial thought as well, but it appears at least one file did have a trojan, and most importantly, don't be downloading from a random file link given to you. A quality company will have an actual website, not a Dropbox or Google Drive or similar. This too screams white label, they have no software team because they have no team, it's a generic file the OEM manufacturer gave them and they can't even be bothered to create a website around it (or make sure it's compatible).
I'm not saying white label is entirely bad, lots of major companies make and sell white label stuff, including brands like LG and Samsung but it can be a problem when someone buys a batch to sell of as a random "company" and disappears as soon as the batch is gone or someone needs help. It is crazy easy for people to do this (email and a credit card) which is why it happens, especially in China where you can start and fold a company in seconds with little recourse especially from overseas buyers. This is also why you can't get much support for it, the company is just a reseller, they aren't designing or making anything, has no department to deal with it, it's likely just one person and they just placed an order. They also may have no support, the "OEM" also may have been a shell company who closed up shop by the time the buyer received their product.
If all this sounds sketchy, it can be, for you and the seller.
If you can, while ordering a white label product (if you know it is one), focus on companies who put effort into it (like Eppomaker and Red Dragon) and at least bother with a website where you can contact them, they're a lot less fly-by-night and much more likely to help when there's an issue.
I hope you get it fixed.
