FCPX and my Flanders Not Happy Together

I have the latest FCPX and the latest High Sierra OS. I use the BlackMagic Ultra Studio Mini Monitor via Thunderbolt to SDI to go from my MacPro to my Flanders Scientific AM210. Recently, we began shooting in 2:1 and sometimes in 2.39. Nothing I do gets the right aspect ratio onto my Monitor. That is unless I am shooting 16x9. Anybody know how to fix this? For reference, DaVinci Resolve has no problem sending the right signal to my monitor in the exact same setup. Whatever DaVinci puts out, my monitor shows correctly. This is on Beta 15 btw....

Edit: This is now on Release 15.1.2.008

www.fcp.co/forum/4-final-cut-pro-x-fcpx/...-aspect-ratio-issues
EDIT:
Since only HDMI seems to work in FCPX , I am wandering if BMD mini converter HDMI to SDI would work

Sorry to say, is not your monitor or card that is causing the problem, we have been talking about this in this other thread: www.fcp.co/fcp-forum/4-final-cut-pro-x-f...t-ratio-issues#97543

Hope you find a solution ore even better, that FCPX has a nice bug fix he he he, let us know!

We are running stereo posts on a unique problematic but with different connection ...

All I am saying is that direct FCPX apple HDMI feed to monitor does not produce the problem , so if we feed this to BMD HDMI to SDI converter and that this device is faithful to this feed , it could work. It would be interesting if someone that has this converter would test that, because the problem for this Flander monitor is that it can only be driven with an SDI connection...