Conectivity issue with atem tv studio hd / atem mini / other

Hy!

I just set up RIG for recording live sessions, but i have problem with signal or conectivity.
I use Atem tv studio hd (8 inpusts, 4 hdmi + 4 sdi) + atem recorder. this is working well, now that i bought right sdi cables to properly connect.
However it seem i cant connect other switcher, to upgrade input possibilyties... Such as: i want to connect atem mini pro (4 hdmi inpusts + 1 hdmi ouput) to one of the inputs of the tv studio hd - in my opinion that should work nicely, but i dont get any signal...
Also had one LIVEPRO L1/L2 form Feelworld and it doesnt work also.
Am i missing something?
I tryed to connect pc/laptop throu hdmi to one of the inputs od the tv studio, and i didnt get any signal also.
All 3 are workih ok,l when i connect directly to one of the hdmi input of lcd tv for example...
Why i dont get signal to atem tv studio hd?

Thank you for the answers...

TVS need all inputs in selected resolution and fps .. WHat is your serut of TVS and MINI ?

yes...that is it.... i just got this info from a friend today, and it works. .. i just needed to adjust the same framerate and resolution... thnx...