Half of Advertised Speed

I regularly get half of my advertised, and paid for, speeds at my modem.  Prior to this week, I was seeing closer to the 2GBps I pay for.  This week, I can barely get 1.3.  

There's no way to contact comcast anymore without reporting an outage, and the AI assistant is garbage.

I am also seeing increased latency spikes and packet loss at the modem in the last week, which is unusual.  Please advise.

I am also seeing that my S33 is *not* showing Orange/Blue, just green, which indicates that I may not be receiving the speeds I am supposed to.  The S33 is a DOCSIS 3.1 modem, and therefore fully compatible, particularly because I can see that I was getting the right speeds before.

To answer the same inevitable questions:
1. Do I have an Xfinity modem? No. I'd rather anything else, so I have an Arris S33.
2. Is this a device problem?  No.  I can see the speeds at the modem are incorrect.  Also, I have an Ubiquiti network, so it would be clear if there was an internal issue.

3. Is this a cabling issue?  That would be highly unusual, considering a week or so ago I was getting my advertised speeds (or at least much closer) at the modem.  I've also reseated the 

4.  Did you try restarting?  Yes.  At least ten times.  

5. Are you testing from the modem?  Yes.  Of course.  My wireless is != to hard wired at the modem and will not reach those speeds.  This is a hard wired problem.

6. Is it the modem causing errors?  No.  Event logs are empty, except for logins.  I monitor for unhandled errors. 

7. Are you splitting your connection?  No.  One cable -> one modem.  

Details:

Edit:

To be triple sure, I plugged a 2.5GE NIC device directly into the modem.