AirCard 785S Mobile Hotspot MIMO setup

I live in a remote area with a fairly weak signal. It's OK for web surfing and YouTube videos but breaks up when trying to recieve phone or video calls. I just setup a MIMO dual antenna system and there isn't much improvement, but firstly I want to confirm that both the antenna inputs are being processed by the modem, but there doesn't seem to be anything (obvious) in the control panel or mobile app to state both antenna are connected. Is there any way I can confirm this?

As an aside, when I do a speed test the upload speed is incredibly poor, compared to the download speed. Is this normal for mobile? They are both subject to atmospherics as the tower is some distance away across terrain.