Hey, I reported a similar problem in my Archer D9. The device showed that it was emmiting at 2.4GHz but my compatible devices were not seing the wifi. Try switching the emission channel of the 2.4GHz...

Model : Hardware Version : Firmware Version : ISP : I want to inform you about a problem that involves connectivity problems with the 2.4GHz wifi band. After 2 weeks from the purchase of your product...