As you mentioned, the Wi-Fi connection dropping suggests that the SBG7600AC2 might be experiencing congestion and high interference. Make sure that the SBG7600AC2 is placed in an open area and at a higher altitude. 

Could you please confirm if it is only the internet connection dropping, or if the Wi-Fi network names are disappearing as well?

Thanks for your reply. I understand what you’re saying about placement and it should be good. Network names are present. States, “Secure, no internet”. 

Therefore, we recommend changing the Wi-Fi channels, as the current ones might be experiencing interference.

Switching to a different channel can reduce interference from other devices and networks, making your connection more stable. A clearer channel can make your Wi-Fi connection more reliable, with fewer dropouts. Moreover, changing to a less crowded channel can enhance the quality of your Wi-Fi signal.

Please refer to the link below for detailed steps on how to change your Wi-Fi channels.

http://arris.force.com/consumers/articles/knowledge/SBG7600AC2-Changing-the-Wi-Fi-Channel