@sinanokatata I would suggest manually syncing the WiFi SSIDs and passwords across your devices, as this allows you to set different channels and other settings for each device. If you only have two devices this isn't a lot of work. I don't think WiFi sync is very useful in small network settings.

Also, I would suggest setting different SSIDs (network names) for 2.4GHz and 5GHz, as your clients may not be able to effectively determine which to connect to if they have the same name.