S33 with Xfinity--No LED when blues should be showing

Xfinity just upgraded me to 800 Mbps (in return for a $10/month fee increase!).  They also informed me, however, that my existing equipment would NOT support such an increase.  In response, I bought and installed an S33, plus a Linksys AC1200, using their 2.5 Gbps LAN ports.  Although the modem seems to be working well, the one fly in the ointment, so to speak, is that, although the LED flashes orange, and then green, when the modem powers up, instead of showing blue, the LED seems to go blank!  In spite of this, however, my internet speed has increased well above the 800 Mbps mark, ranging from 900 to about 912 Mbps, and seems to be working smoothly!  I do know that the area where I live is on the outer fringes of their network in this area.  Could that have something to do with the LED not showing blue?  In any event, how should I proceed?  Thanks in advance for any advice or assistance!