Slow to Zero Upload Speeds Area Wide

Twice in the last week, I've had issues of upload speeds being insufficient...when I'm able to get a speedtest site to load, it measures between zero and 0.3 mbps.  Download speed is good.  A review of cable modem status shows everything in tolerance.  When the problem occurs, I've tried logging on to a nearby Xfinity hotspot and visiting a nearby business and both are experiencing the same issue.  After long discussions with 1st level support, both times I've been able to reach 2nd level support.  Shortly after contacting 2nd level support, an area outage was declared and the problem was resolved in about 15 min.  2nd level support says that they "refreshed the services in the area".  After the 2nd time, customer service insisted on a technician visit.  The technician found no signal or connectivity problems and couldn't explain what was occurring or what 2nd level support was doing to fix it.  Any ideas what's happening?