4KIP100-KVM only connects video with "some" sources to LG 49SK8000PUA screen

I have a 4KIP100-KVM and it works for some PCs but not all of them.
The screen i am hooking up to is an LG 49SK800PUA and that is not the issue.

The transmitter works for my laptop and my wife’s, but we have a smaller Thinkpad that it just won’t work for. I also have a small form factor PC that I would like to set up in the tech closet to run content on, but it won’t work on this one either.

So i know all the settings are good and it is connecting because i can get it to work with some devices, but not the ones i want it to work with.

We are running it over the network.

Is it an EDID thing? an HDCP thing?
What gives?

Hello Joe,

Thanks for reaching us,we are so sorry for the issue.
As your testresult,our device is working fine and something with the Thinkpad and the factor PC.
Our device support HDCP 1.4 so that may not this HDCP issue.
How your thinkpad and mini PC connect to the transmitter when you testing? is the straigh HDMI cable?
How about try direct connect them to the monitor and bypass our KVM extender to have a test?