5% upload speed on Sophos UTM

First off let me say I know this has been a frequent question posted here regarding slow upload speeds on the UTM.  I have been a UTM user for well over a decade probably closer to 15 years.  I may not be a Bob expert but I know my way around the software. 

I recently got an ATT symmetric 1GB fiber line and plugged it up to my UTM VM.  At first, performance was normal and expected.  I was getting close enough to max throughput with the understanding that I would be getting less because it was running in a VM on older hardware.  All fine.  Then one day, and I honestly don't know when, upload performance just took a nose dive.  I would get 3-5Mbps on uploads.  Sometimes spiking to 7%.  

I did all the normal things, turned off IDS, turned off web filtering, confirmed 1500 MTU on all NICs, you name it.  I have a small Ubiquiti FW as a backup and it was able to get full 1Gb from all my VM's and my physical boxes, so I know my internal network is fine and can handle it.  I even built not 1 but 2 brand new UTMs.  One I did a restore of a config and another I did unconfigured, no settings.  The performance of all these UTMs is the same 5Mbps upload.  Download speeds are fine and close to theoretical maximums.  I am at a complete loss.  I do NOT want to migrate my services to Ubiquiti.  I want to keep using the UTM. What else can I do?  there are no IDS or filtering logs to check since all of that is disabled.  Is this an ATT thing?  Is there some special setting I need to make on the ATT FW or UTM interface setting I need to make to get this to work?  It doesn't have to be perfect, but symmetrical upload is all I want.