How are you sending video to OBS/VMIX? If there’s no lag in Aximmetry, but in the receiver end, it’s probably not an Aximmetry issue. 

There many ways to send video?

Yes, and RTMP isn’t one of them! Why would you use that to get video into OBS/Aximmetry? The most professional and stable way to do it would be to run Aximmetry and OBS on two separate computers, each with a Decklink capture card for output/input. The most practical option would be to use NDI. Last option would be to use SRT, but I don’t know why you would choose that over NDI.

OBS and aximmetry on different PC and i have capture cards, sadly, not decklink ones.

I can't use NDI, because i`m on studio edition at the moment, i can pay up for NDI plugin, it will help for sure? )

Why not use the capture cards out from Aximmetry and into OBS? NDI will definitely be a much better option than RTMP.  We use it in our studios for monitoring and don’t get any lag. 

Thank you very much) Will get NDI than ) To use capture cards i need professional edition and up) Still a newbie, will buy it later on for sure)

You can use capture cards with HDMI in any edition. 

Hmm, need to check this option than, didn't found how to use it, unless i want to fully capture my screen. (not an option in my case)

What capture card do you have? You should really read the documentation, there’s a lot to learn. 

Got it working) It was cloning monitor 4k/120 fps, uncloned it and set 4k/25) Will check full perfomance later on. On the first glance - alot better than RTMP)

Thank you, will check NDI later on too!