I have problem that I cannot find answer for even after few days of searching. I have hAP ac with os version 7.1.1 (but problem was even on 6.9.2) as my main router. It is configured as Home AP dual with both 2.4 and 5Ghz wifi set with same SSID and password. It was working for a long time as this with no problem. Now, I have moved to bigger house and the range of hAP ac is not enough. There are two rooms with very bad or no signal. So I have bought an hAP mini, configured it as WISP AP in bridge mode with static adress through LAN and with same SSID and password for 2.4GHz as hAP ac. Everything worked for maybe two days and after that I was seeing degrading of 5GHz wifi service, first the speed and after that some devices were unable to work on 5GHz (for example mobile phone showed that it is connected to 5GHz and nothing works, I have set ACL to force this phone on 2.4GHz and everything is ok). When I disable 5GHz or force the devices to 2.4GHz everything seems to work. But I don't understand why. And one more thing, there is literaly no interference from another network on both bands. I was going around and there is no other network in range of my APs. Both APs are set to different channel (6 for hAP ac and 11 for hAP mini and only 20Mhz). Can anyone explain what is happening in my network?