GIGABIT: 2 Home Networks after Replacing Modem

GIGABIT Trouble:
Due to an electrical storm/lightning, I am now on my fourth Gigabit modem from Comcast; and the same low flow persists; not more than 115 download hardwired.

Here's what I notice: I NOW Have TWO Home Networks;

my usual home network, and the same network with a '4' after it (signifying the fourth modem). 

Upon looking at the properties of both,

the '4' network is rated for gigabit speed,

the other home network is rated for 300 send/receive.

Even the supervisor on the phone said that was odd...

Has anyone else seen this issue?

I am now using

Cat8 Ethernet Cables, and

GE Quad shielded RG6 Coaxial.

QUESTION: RG11 - Has anyone Run RG-11 Straight to the Modem? It's about 12 feet from the closet where the cable comes in, to the modem. I currently have the coax going into, and out of a surge protector for added em/filtering.   This is what I might try next, unless someone else has tried it and realized it doesn;t work due to reflection? signal bounce?    Anyway, I might buy 15ft RG-11, run it from the closet to the surge protector, and run another (3ft) RG-11 from the surge protector to the gigabit modem.      YOUR THOUGHTS, PLEASE?

THANKS!!