Pbk22

We presume you mean RBK22?

Orbi works with most ISPs.

Modem Combo Units:
This would be a double NAT condition which isn't recommended. https://kb.netgear.com/30186/What-is-Double-NAT
Couple of options,
1. Configure the modem for transparent bridge mode. Then use the Orbi router in router mode. You'll need to contact the ISP for help and information in regards to the modem being bridged correctly.
2. If you can't bridge the modem, disable ALL wifi radios on the modem, configure the modems DMZ/ExposedHost or IP Pass-Through for the IP address the Orbi router gets from the modem. Then you can use the Orbi router in Router mode.
3. Or disable all wifi radios on the modem and connect the Orbi router to the modem, configure AP mode on the Orbi router. https://kb.netgear.com/31218/How-do-I-configure-my-Orbi-router-to-act-as-an-access-point and https://www.youtube.com/watch?v=H7LOcJ8GdDo&app=desktop

Recommend modems with out built in routers if possible.

I know someone in Greensboro, NC who has an Orbi connected to gigabit fiber.  I am not 100% certain that the service is from Northstate, but I know that some telco from the High Point area dug up every street in Greensboro installing fiber. 

If you are in the High Point area, I think it highly likely that the RBK22 will work fine.