The problem with 5 GHz has not been resolved in 2 years? 4011 works without problems only when 5GHz is disabled. But I bought this device to use 5GHz. Otherwise, I would buy a cheaper version of 4011 without wireless modules. Mikrotik engineers are still trying to solve this problem or abandoned thi...

Same problem on this device (RB4011iGS+5HacQ2HnD-IN). I changed the firmware - it did not help. It is now 6.43.14. Interface settings changed, changed channels, etc. Reset to default settings. All this does not help. It usually works up to 4 days, then the interface is "S without R", but the SSID is...