Third Arris Surfboard won't connect to internet.

Last saturday my Comcast / Xfinity connection died. I was using a gen 1 SB8200. The error code of the flashing lights suggested that the modem was borked, so no biggie, I just ordered a replacement one (to show up next day, and an S33 arriving a couple of days later).

The new SB8200 arrives, and when i plugged it in, i got the power light, then all four lights would blink green, then nothing. No connectivity. My router (Archer AX50) reported that there was no WAN connection present. Worked with Comcast to get this new router on my account but still nada. They sent out a tech who replaced cable from the pole to my house - still nothing. The S33 arrived and had the same problem. The tech sent someone to look at the TAP on the pole - there was some water damage but its fixed. Everyone else connected to that TAP is working. The tech came back the next day - replaced another section of cable, but I still wasn’t connected. They plugged in a Comcast modem and it connected and worked. Both my routers were refurbished - and I read that sometimes routers that have been used before can exist on someone else’s account in Comcast, so I worked with tech support to get that cleared and only have the modem on my account.Still the same.

I ordered a brand new Surboard SB8200v3 - that arrived today, still the same. I have one more cable model arriving today - not an Arris, just to test. If this doesn’t work i’m switching to Verizon.

@Xfinity Support @XfinityDilary