Image flicker with DeckLink Duo 2

Hi !

I am experiencing this intermittent image flicker problem :

It happens roughly every 1-2 minutes but not regularly.

All 4 cameras in my live broadcast setup are affected.

Setup description:

Cameras : Sony Alpha 5100 with HDMI output
Converters : Blackmagic Design Micro Converter HDMI to SDI
Capture : DeckLink Duo 2
PC and software : Linux Mint with OBS

I don't experience this problem when my cameras are connected using Elgato Camlink (HDMI -> USB) using the same PC with OBS.

So I suspect the DeckLink Duo 2, some incompatibility with Linux or some hardware problem. Maybe the converters (but not 4 of them can be faulty) or the SDI cables (but again, not 4 of them can be faulty).

Unfortunately, I don't have another PC I can try, or another DeckLink Duo 2.

Do you have any idea of what might be causing this issue? Or what steps I could take to pinpoint the part responsible for the image flicker?

Thank you for your help!

Does it mean anything at all that the glitch always happens on the lower half of the image?