It may be the Streaming.xml file that is broken?
Try connecting the ATEM Mini Pro that works and extract the Streaming.xml file (copy it to your desktop). Than connect the ATEM Mini Pro that does not work and replace the Streaming.xml file by the one that works.
Here is a guide to where you can find the Streaming.xml file:
https://heretorecord.com/blog/custom-st ... m-mini-proI have also added the latest Streaming.xml file to this reply.