Placed my first order with bitmain today paid immediately after. Transaction is verified on blockchain yet order status says Unpaid Unshipped Expired. I've sent them a email with transaction id should I be concerned or is this not uncommon?
This happened on an order I placed earlier in the week - I sent an email, and about an hour later it was updated to show that the order was paid. It arrived, on time, today. Hopefully you have similar luck

I believe my email was during business hours in China, fwiw.
This same thing happened to me today. 20 confirmations so far and I already emailed them (no reply yet). If nothing changes by tomorrow do you have any advice on what to do?