Issue with return on BMSCPRO6k and Mini Extreme ISO SDI

Hello, we have 4 BMSC 6K Pro cameras connected to an Extreme ISO SDI. All cameras are updated to firmware 8.2 and the switcher is also updated to the latest firmware. We connect the four cameras with dual SDI for input and output. But randomly, some of the cameras, when we press the PGM button, all we see is their own camera signal without the OSD. Switching the output to bars also doesn't work. We have tried changing cables, changing input and output ports, avoiding specific inputs on the switcher... Nothing works. Some cameras freeze when the program button is pressed, and camera control and tally also stop working when this happens. Occasionally, turning off and on the switcher fixes this issue. In other instances, turning off and on the camera also fixes it, and sometimes just removing and reinserting the SDI cables makes the camera work perfectly again. But sometimes none of this works and we have to do it multiple times. There is no consistent pattern of behavior that always resolves it. We are already desperate because we have tried everything. Connecting it to a single output, using an SDI switch, connecting it only to the switcher outputs, resetting the cameras to factory settings, resetting the ATEM to factory settings. None of this works. Has anyone else experienced this? Is there a solution?

UPDATE:

We have tried removing the optics from the cameras, in case it was a problem with the Sigma and Canon optics electronics. The issue persists. As a final test, we replaced the Atem Extreme ISO SDI with our old Television Studio Pro HD. With this switcher, everything works correctly. The return feed, tally, and camera control function properly and do not hang despite several attempts to restart both the switcher and the camera. All is well, which leads us to believe that the issue lies with the ATEM Mini Extreme SDI. Hopefully, it will be resolved in future updates. Between this issue and the artifacts during recording mentioned in my previous post, the switcher is currently completely unusable.

[Gary Adams]

Hello Alberto. This is not normal but makes me curious. Please check that the ATEM switcher video standard is "Not" set to "Auto". Please set this to your desired frame rate. Then The cameras may each be set to either Internal or Program reference. If by any chance one or more cameras are set to Program reference, and the ATEM is set to Auto, there could easily be a sync feedback loop causing what you are describing. Maybe that is not the problem, but worth a quick verify. This condition would not happen on your other ATEM because it doesn't have the Auto mode for format. I hope this helps.

Gary

Thank you for your answer.
Atem was always at custom mode in 1080 50p. Cameras set as same frame rate and resolution and internal reference. Program hangs still at Radom camera. If we restart cameras several times it finally takes program signal. But if we restart the switcher, problem continues in random camera. We tried to shut on before Atem and after Cameras. Not working. We tried to shut on before cameras and after ATEM. Not working.
We don't know what to do.