Xfinity Internet + G34 Modem + Eero 6 +: Bridge enable issues and SLOW wifi speeds

Hello, 

I have the following setup: 

• Xfinity Internet of 1GB 
• Surfboard G34 Modem + Router Combo 
• 4 Eero 6+’s 

I have the following 2 issues: 

1. When I enable bridge mode on my G34, my eeros no longer work and cannot connect to the internet. As soon as I disable the bridge mode everything works fine. I have been on 5+ hours of support with both xfinity and eero and still cannot resolve this problem 
2. The above problem stemmed when I identified through a speed test that directly from my modem my internet speed is always ~950mbps, however when I run speed tests on my wifi with my eeros connected my speed is around 120-170mbps. This is a HUGE drop. I was trying to trouble shoot and hence backed into the above enabling the bridge mode which I cannot do and there are no other solutions. 
   1. Even when I check the speed from the 2 networks that are pushed through the G34 those speeds are even slower ranging from 100-120mbps. So its not just an eero problem.

Can someone help/lead me in the right direction? 
I have confirmed this is definitely a modem problem with the G34. I have read that the G34 and eeros don’t really talk well, but weird that I still see the same issues with the internal networks they create. 
Is this just a bad modem problem? 
Is there a better modem I should buy? 
Are there any configurations I may have skipped? 

Any help is greatly appreciated!