connect airport extreme wirelessly to existing fios network

Hello. I apologize upfront if this answer is posted and I have missed it. I've been searching... and I've tried some solutions without luck.

My situation: Until today, I had my Airport Extreme 802.11ac hardwired into my new Verizon Fios Gateway G1100 router. I do this as I have some Airport Express extenders (connecting to an Apple TV and a TiVo) elsewhere in my home. I've consistently had inconsistent wifi service, which I could remedy with a daily reboot of the Gateway. As of today, the wifi did not restore following rebooting. A Verizon tech came out and said that "error codes" had built up to the extent that it had shut down the Gateway. In his opinion, this was caused by the Airport Extreme connection (and some kind of error code transmission between the devices) and he recommended I disconnect the two.

My question: Is it possible to connect the Extreme wirelessly to the Gateway so that the Extreme can still send a signal to the Expresses? If yes, how? If no, does anyone have any other ideas (I'd really rather not have to buy some other extenders and a tivo wireless adapter). As another alternative, does the Verizon tech's theory make sense? If yes, can I prevent these codes from transmitting?

THANKS!