I was unfamiliar with Tenda.
> Shenzhen Tenda Technology Co.,Ltd. ( https://www.tendacn.com/us/profile )
Tenda may just rebrand, right? It seems like many chinese brands will either rebrand or have a 'competing' brand with the same internals but different externals. (I have no idea if Tenda does this, I've just seen it previously. Specifically with security cameras)
I wish the authors provided some method for checking this vulnerability other than fw version. It seems like Tenda could just change the password and say "yep! all safe now"