Chronic Intermittent Loss of Upload Speeds

This issue does seem similar to others I have seen posted here in the forums.

We have had comcast internet at our home for about 3.5 years now.  The first 3 years or so were perfect, with no issues.  However, for the last 6 months and counting, we have been having bad intermittent issues.  The primary problem is that Upload speed of the entire home drops to 0 or to extremely low numbers, or fluctuate very quickly in which we get kicked out of work meetings or streaming stops entirely, etc.  We often get the "No internet Connection" popup on all of our devices..  The issues can last for a few seconds or up to ten minutes.  On average this happens every day, sometimes multiple times per day.  Sometimes things are just slow, other times we do not have any internet connection at all for the duration.

We have a Netgear CM1000v2 modem, and we have now noticed that whenever this issue occurs, the "Uplink" light blinks for a while until eventually going solid again, and then connectivity resumes.

We have had comcast techs out four times.  They have rewired the connection from the Comcast source box to the modem, replaced connectors from the street to the house, changed splitters - you name it, and this issue keeps occurring.  As remote workers, this has become a huge issue for our work.   We are at a desperate stage.  

We are turning to the forums in hopes that somehow this has been seen before by different teams or different customers that managed to get it resolved.  Thanks for any insight or assistance.