BM 4K STUDIO PRO. SDI-in seems stopped working.

Hey, folks! Sorry if this topic already was discussed in the past, but I couldn't find anything useful about my situation.

SITUATION:
We're running multicam live production with next stuff:

- Four 4k studio pro cameras,
- ATEM Constellation 1 M/E HD,
- SDI Distribution splitter.
- Some other stuff like smartvideohub 20x20 and web presenter 4k.

The issue is two of our cameras stopped getting settings and tally from the constellation. Three months ago one this happened to the first camera and yesterday exactly same thing happened to the second camera. Color settings and tally work fine while camera is connected to ATEM MINI EXTREME (HDMI) but I can't operate it when the camera is connected to constellation with SDI.

Things I checked which have not worked out:

Cables (are totally fine)
Tally LEDs (work fine being connected to ATEM mini with HDMI)
Factory reset (didn't help)

Am I missing something? What could be a reason? Does anyone met this problem?

Thanks in advance!

Someone hasn't changed the ATEM Camera Control settings or camera ID numbers by accident?

Do you get the correct Atem output video shown when you press the viewfinder PGM button? If not, if you plug a monitor into that feed, does it show correctly there. This should help you find out if the correct signal is actually getting to the camera.

Someone hasn't changed the ATEM Camera Control settings or camera ID numbers by accident?

Do you mean mapping? Seems fine to me. Also IDs are totally okay.
I suppose the problem is in the camera itself because when I connect another BM 4K Studio Pro instead of it - everything works as it should be.

Do you get the correct Atem output video shown when you press the viewfinder PGM button? If not, if you plug a monitor into that feed, does it show correctly there. This should help you find out if the correct signal is actually getting to the camera.

I've just checked it and yeah, the monitor displayed feed absolutely finely. The camera operates like there's no input signal at all but... there actually is.