Internet down for months

Hey all,

I’ve been having an internet issue for months, and I was gone from my place for 3 months due to covid. Now that I’m back the same issues are still there and are frustrating.

Essentially, it began with my internet dropping for several hours a day, only being working for a few minutes until it drops again for hours. I notice the modem being stuck at the uplink light blinking, and sometimes the downlink (but mostly uplink around 90% of the time).

My network setup is: Modem>going into UniFi USG via WAN>USG via lan to unifi 8 port switch> switch goes to cloudkey gen 2 and unifi ap ac pro, with my Mac Pro connected via lan to the switch.

I’ve tried power cycling my modem, factory resetting all my equipment, but it never seems to work. My Mac shows an IP, DNS, all that. I suspected it may be my modem, so to rule it out I connected my Mac Pro correctly to the modem, and changed the MAC of the Mac to that of the modem, internet worked fine.

I then thought it may be the unifi gear, so I connected one of my old routers (Asus ac) with a typical setup, but the modem light still blinks the same way and I can’t go to the internet.

I said screw it and exchanged my modem (Dlink cm1200) for the Arris surfboard SB8200 since I had the Best Buy replacement. Activated it, no luck, and the same blinking light pattern.

I’ve contacted support for my ISP multiple times, and they all take me through the same steps and then refuse to send out a tech to check my lines. They tell me it’s my equipment and I should contact the equipment manufacturers

At this point I’m looking for help because this is extremely frustrating as I’ve had no working internet for a long time. Any input would be appreciated.