Mofi 4500 being throttled on Visible?

[Kuato]

I've been using a Visible sim in a Mofi 7730L and getting great speeds (7mbps average). I bought a Mofi 4500 thinking it would get the same and be a more reliable device but oddly it greatly underperforms. On average the Mofi 4500 with same sim and correct settings averages 2mbps down. I've tried different bands and TTL settings.

My theory is Visible is throttling the Mofi 4500 as hotspot data but not throttling the Mifi 7730L. Anyone experience this? Any remedy? Likely returning the Mofi 4500 if I can't get it to do better than 3 year old Mifi hotspot.