ATEM Constellation HD Won't Display Output

We recently purchased an ATEM 2 M/E Constellation HD to replace an ATEM 1 M/E Production Studio 4K (we needed the 2 M/E more than the 4K capabilities). Never had issues with our old unit but upon hooking everything up the same way to our ATEM 2 M/E Constellation HD, we cannot get anything to output without the use of a decimator. I've called Blackmagic, reassigned outputs, changed video standard, and everything else I can possibly think of and can only come to the conclusion that there is something wrong with the unit. The decimator has an LCD screen that shows the input signal and so I can see that I'm receiving signal and what quality the signal is. So the device is outputting somehow but it won't show up on any of the receiving devices without a decimator. I've sent the output to the rack mounted Blackmagic Dual monitor device, a TV, and our FLMHD20 projectors.

Again, never had any issues with our previous device and I hooked everything up the same way. Please tell me I'm an idiot and am missing something so incredibly basic. I assumed it would be plug and play.

I'm betting on Level A vs Level B output in the Switcher settings. Most equipment uses Level B, Decimators are able to convert between them.

Or maybe REC2020 color space and some devices don't show video that is outside the legal levels?

I'm betting on Level A vs Level B output in the Switcher settings. Most equipment uses Level B, Decimators are able to convert between them.

Or maybe REC2020 color space and some devices don't show video that is outside the legal levels?

Thank you for the response. You're right that the decimator sees the change and scales it to whatever I ask it to but when I go straight into the projector, bypassing the decimator, changing A and B doesn't make a difference. I am curious about the color space. I can't find any info on the Production Studio 4K color space...if different, could that really be the thing preventing an image showing up? Seems like at the very least the black magic dual screens wouldn't need something to convert color space to show up...I dunno.

What video settings do you use ?