OpenVPN iPhone app: connected but ultra slow. Good speeds on Macbook

[Cabledude]

Hi all,

I created an OpenVPN Server on my Netgate which works great when I connect my Macbook, but the iPhone OpenVPN app is painfully slow. These are my connection methods:

A1 Macbook WiFi
Using viscosity app + WiFi to connect to internet:
Macbook -> Viscosity client -> WiFi -> Internet -> Netgate
Result: connected and good speed

A2 Macbook iPhone tethering
Using viscosity app + iPhone tethering to connect to internet:
Macbook -> Viscosity client -> iPhone (tethered) -> Internet -> Netgate
Result: connected and good speed

B iPhone
Using OpenVPN iOS app on iPhone:
iPhone -> iOS OpenVPN app -> Internet -> Netgate
Result: connected but very slow (can take over a minute to load the pfSense dashboard)

This is the same OpenVPN server and both devices connect.
The iPhone does connect:


Do I need different settings for iPhone?

Thanks!