Full screen output not displaying to secondary output

It’s been a long time since running Mimolive not through a Blackmagic ultra studio. Today I encountered a big issue running a full screen output using THB3 - HDMI output to Decimator LX HDMI - HDSDI convertors.

When trying to output fullscreen to my secondary monitor output the output window would only appear on the laptop LCD screen even tho the external monitor was selected.

I was running 2 Identical 2018 15"MBP Mac OS 10.14.6. mimoLive ver 5.4.

I changed multiple THB3- Hdmi Adaptors, various cables, looping through a field monitor and an alternative HDMI- HDSDI convertor. The desktop on the secondary output was visible and selected within the Mimo output destination but the fullscreen Mimo output would only appear on the MBP LCD monitor.

I Have noit seen or heard of this before, hoping someone can point me to a fix as this situation is very disconcerting. I have several more days with this same set up to come until my Ultra studios become available.
Both PVP3 and PBPP worked fine to the secondary output.
As a work around set mimo to output NDI and used an NDI input on PVP3. This certainly worked , it kept me on edge for the day,
any suggestions appreciated,

winnie, sorry to hear about the troubles. Can you please post a screenshot of how you set up the Full Screen Output Destination?

Can you also please send me the System Profile of the Mac with all the devices attached? (https://docs.mimo.live/docs/system-profile)