New install, blinking yellow light on modem

Background Info:

• There is an existing Xfinity modem within my household under a different account
• I chose this plan for easy install, especially given there is already a connection to our house
• I received and attempted to set up the modem the same day, 12/15/2025

Things I tried (in order)

• Normal activation: Scan QR code > plug in coaxial cable in upstairs outlet and modem > plug power cord in upstairs outlet and modem >wait five minutes [Light goes from solid yellow light to blinking yellow light]
• Double checks all wires to ensure they're secure
• Unplug everything > wait a few minutes > plug everything back in > wait five minutes [Light goes from solid yellow light to blinking yellow light]
• Unplug everything > wait a few minutes > Enter CM MAC manually > plug everything back in > wait forty-five minutes [Light goes from solid yellow light to blinking yellow light]
• Unplug power cord > wait a few minutes > plug power cord back in > wait five minutes [Light goes from solid yellow light to blinking yellow light]
• Check for outages in my area via Xfinity AI Assistant > says there are none
• Troubleshoot via Xfinity AI Assistant > says no issues, suggests scheduling with technician > choose not yet, would like to resolve on my own first
• Unplug everything > go to existing modem downstairs (kitchen) > unplug existing modem > replace existing modem with new modem > scan QR code > plug in coaxial cable in wall and modem (used existing modem's coaxial cable) > plug power cord in wall and modem (used new modem's power cord) > wait five minutes [Light goes from solid yellow light to blinking yellow light]
• Unplug everything > return upstairs > scan QR code > plug in coaxial cable in upstairs outlet and modem > plug power cord in upstairs outlet and modem > wait five minutes > hold reset button for twenty seconds [Light goes from blinking yellow light to blinking blue light, before returning to blinking yellow light]
• Wait five minutes > hold reset button for twenty seconds again [Light goes from blinking yellow light > solid green light > rapid blinking green light > solid yellow light > blinking yellow light]

After this final attempt, I left it plugged in overnight hoping it just needed more time. I checked again around eight hours later and there are no changes. I am now at work, and it is still plugged in. I would prefer not bringing in a technician, but if absolutely necessary I suppose I don't have a choice. Hope to see a response soon!