EXTREMELY slow tethering speeds

Is anyone experiencing problems with tethering speed?

 

Thanks to work at home and weekend storms that knocked out power and internet for thousands in Nashville, the only option I have for internet at the moment is my xfinity mobile phone.  When I test speeds on the phone, I am consistently getting speeds in the 10-30 Mbps range.  These aren't spectacular 4G speeds but at least speeds I can work with.

 

Unfortunately, when I try to tether the phone to ANYTHING, the speeds I get are horrendous.  I have tried an ipad, an android tablet, and a windows PC via wifi, as well as USB tethering to the PC.  In EVERY case, speeds fall to around 600 Kbps or less.

 

I am on the By the Gig plan, which is supposed to provide LTE speeds when tethering.  (I have used less than 2 gigs this month so I have not hot the 20 gig threshold when I get throttled to 1.5 Mbps.)  It is abundantly clear that my tethering is being throttled.  I'm sure it is no coincidence that I am getting throttled to the 600 Kbps speed provided to the unlimited plan.  Yesterday I spent 90+ minutes on the phone in 4 separate support calls with no resolution. 

 

The first rep told me that 4G tethering was not enabled on my account.  She turned it on and we thought the problem was solved but speeds did not improve.  The second call got disconnected a few minutes in with no progress.  The 3rd call switched the 4G tethering again and reprovisioned my line, but again speeds did not improve.  The 4th call I got a customer service rep that was a real jerk.  Even though the system clearly wasn't performing as it should, he just told me that they had tried all their troubleshooting so there was nothing he could do.  I eventually convinced him to elevate the issue to the next level, but we did not get a reply.  Eventually he lied to me and told me that the first rep had already consulted the next level of support, but this was not true.  The first rep never left the line with me so I know she did not speak with anyone else.