I switched to Arris SB 8200 modem from the default Comcast modem and Velop can't get a DHCP IP address.
Old setup which works
Comcast Modem/Router in Bridge mode -> Velop
New setup which can't get the DHCP IP
Arris SB 8200 -> Velop
Arris SB 8200 shows that it is online and I can connect a computer to the ethernet port on the 8200 and browse the internet.
The XFinity support person had setup the new modem via Chat with the new MAC address and activated it. All lights on the SB 8200 are solid.
Thanks Bob. I tried that.
Disconnected ethernet cable from Velop to modem.
Turned the modem off and on.
After 5 mins, attached ethernet cable back and turned on Velop.