Up load speed below 10Mbps after Xfinity upgrade

I am on the Superfast plan (800/20). Since the plan change to 800/100 my modem upload speed has been reduced to 10mbps, it actually varies below that speed.  My download speed is very good, meets or exceeds my plan.  I know that the software used to change the upload speed had problems and has caused even those with Xfinity XB7 modems to be affected.  This has also caused problems with my home security protection. Iam looking for this to be corrected soon. Can you help?

My modem is a Netgear CM2000 (2.5g down/1g up) which has performed very well on the Superfast plan up until the upload speed change.

additional information:  I have connected directly to the CM2000 with a Cat6A cable from a computer. I also used another modem (same configuration) and ran speed tests with it. No difference in outcome. Download speed are as expected for plan, but the upload speed is not.