Lost feeds over HDMI

[Mart68]

So i have got myself a Hikvision 7616NI-I2/16P NVR to replace my Hiwatch 216M-A/8P.
I have 11 cameras on my system. 5 Hikvision 2055 and 6 Hilook D140.
9 of my cameras connect to the NVR via PoE port and all are working as they should.
But i have one 2055 and one D140 using the same cable via a TP-Link splitter into the LAN port on the NVR.
I have them both connected to the NVR and working. But the video feeds are only working on the VGA monitor and my laptop for those 2 cameras.
To my HDMI monitors the 2 going into the LAN port have just disappeared and are not showing.

 

[Mart68]

So after spending some hours trying to sort this out, i ended up running another cable to split the 2 cameras up.
This was a pain to do but everything is now working as it was before i changed the NVR to the better model.
But if anyone knows why i was getting this small problem with these 2 cameras not showing up over HDMI would be helpful.
I will be adding some more cameras and would like to use one cable over the long runs.