Major drop in speed, 3Mbps

Technical Support for Routers
1

My little 750s has been great but yesterday I noticed that pages were taking a while to load, like DSL days. I started looking into it and I wasn’t getting more than 3Mbps, so I did a firmware update. That didn’t work and I ended up having to install the firmware manually. Got everything re-setup and configured (no add-ons) and still the same results. I checked the modem several times and all was/is good. So I plugged in my old TP-Link and bang, 50Mbps.

Any ideas? Should I return for another one from Amazon? I am still in my return period.

Thanks

2

Are you using cable or repeater?

3

I was using a Surfboard Modem in bridge mode cabled to the 750. It would take forever to get the DHCP address from Comcast, usually having to take each unit down and then back up. I finally gave up.
I returned it back to Amazon this morning. I have a RPi 4b I will see if I can get up using OpenWRT.
Thanks for the response.