Asus customer support has an absolutely terrible reputation. For me, I was getting useless responses from their customer 'support' team on a Z97-K motherboard. Eventually I just got fed up and sold the board.
Hope you get it all sorted out soon.
There's a really nice looking X570 mini-DTX motherboard from Asus, but it being an Asus product is really making me think twice as to whether I'll go for it.
I had the same experience they wanted you to upgrade the board for NVMe support, Gigabyte did it with a bios update. And Gigaman is an active rep too not many spring to mind him and L.G Daniel? How do they do it as in being bad compared to Gigabyte etc? And people think ROG and things are premium!
I am 99.99% sure my next build will be Corsair and Gigabyte graphics and motherboard and the Gigabyte Aorus 240hz monitor as well. I think they deserve it they were first to market i think with 0.5ms panels.