Summary

I recently upgraded from and ER605V2 to the ER707M2 after a sale and initially kept the same settings.

I have a gigabit connection through Verizon.

Originally had the ER605V1 and was not getting full download or upload speeds.  I borrowed a friends spare ER605V2 to find that I got better but not full up and down speeds.  With ER707.  

Symptom

1. From what I can tell
2. All wired clients are getting full up and down speeds
3. WLAN connections that are able to reconnect are getting full down but limited upload speeds.
4. When I run speedtest.net the WLAN upload speed will do a split second burst up to where it should be and throttle down to 4mbps and eventually drop down to 0.8mbps-1.5mbps
5. This behavior was not present with ER605V2.  WLAN speeds topped out around 90mbps

Topology

VZW ONT  -- >  ER707-M2 v1.20 -->  SX3008F v1.20  -->  TL-SG3210XHP-M2 v1.0  -->  EAP660HD

• VZW ONT connected to ER707 WAN Port6
• SX3008F v1.20  Connected to SG3210XHP-M2 v1.0 via SFP+ DAC

What I've tried to change with no resolution in symptom

1. Changing ER707 WAN port from 1 - 6 with manual connection speed
2. Changing manual connection speed from TL-SG3210XHP-M2 v1.0 --> EAP660HD
3. Toggling Flow control on ports
4. MTU --> 1400 on WAN
5. Manually set bandwidth control to speed of ethernet port
6. Disabled Attack Defense
7. Verified Firmware updates - OC200 is only one left.  It refuses to download update

Has anyone encountered this specific "burst then stall" upload behavior when changing from ER605V2 to ER707-M2?  Thanks!