Different output signals from Mini Pro and Extreme?

I just upgraded to an Atem mini Extreme from the Pro. I had a monitor that worked great on the Pro from the HDMI, and I could set the pro to any output frame rate and the monitor would display no problem. When I attach the same monitor with the same cable to the Extreme, I only get an image if I set the Extreme frame rate to 1080p 50 or 1080p 60. All other frame rates and the monitor says unsupported signal. Does the Extreme have something different about its output form the Pro that would make the monitor not recognize the signal? I’d like to set up my extreme to export at the frame rate I want, not at the one I have to export to just to see my multi view. Is there a setting I’m missing to make it work at the lower frame rates?

Thanks

This is the monitor if it helps

I’m using a similar display for mulitview and I must admit my switch from the Pro to the Extreme hasn’t been flawless with this. I swapped the cable and it did fix the problem, but now it seems to work fine with either cable, which is worse! Cos I feel I can’t totally trust it.