Powerline Connection - Multiple IPC Issue

Hi guys I am a total newbie to this sort of thing I am literally just helping my Dad set up his CCTV as I am fairly tech savvy but I am having issues using some cameras we have via Powerline adapters.

We are using:

Dahua NVR - DHI-NVR4104-P-W

Cameras

Dahua - IPC-HDBW5302

Dahua - IPC-HDBW5302

Nexus IPC - IP-390DMI-3.0MP

Nexus IPC - IP-390DMI-3.0MP

2 x Pairs of TP-Link Powerline Adapters (different models and synced seperately)

2 x PoE Injecters

So basically we have 2 cameras directly into the NVR which work fine, no problems with those.

The issue lies in ones we have in the garden. We have two cameras out at the garage, we have two pairs of Powerline adapters working independently of each other which come back into the house via the garage plug sockets and both then into the NVR.

Now if I plug and pair one set of Powerlines and plug in a camera it takes a little while for the NVR to find it but it does eventually appear. Now if I sync and attach a second set of Powerlines and a second camera from the garage it just doesn't want to play ball at all. We did at one point in the past have them both working (kind of), however after unplugging everything to finalise wiring etc and plugging them back in it has never been back on, and when it was all working the two from the garage were really choppy video. Also worth noting that when both Powerlines are synced at the same time, even though the 4th camera doesn't appear, the video on the 3rd goes choppy.

I realise I may not have explained the current setup that well so I did a quick diagram of what I have:

Now is there a problem with us using two sets of Powerlines over the same section of mains wiring? I seems like they are fighting each other!

I was thinking would it work to have a switch in the garage with both cameras going into that and then over the one Powerline back to the NVR? Would that be a better option? Would both cameras appear independently?

I am open to suggestions as I am lost at the moment!

Sorry for the long post I just wanted to try and explain my problem as best I could and hopefully I am posting in the most relevant section!

Many thanks!

If you have synced both sets of power line adapters to each other, you have made a network loop with them both going into the NVR. You should only need 3 powerline plugs, one at the NVR, and one for each camera.

If you try to run 2 independant sets of powerline devices in the same electrical system then you will still have them colliding with each other. The syncing of them is just for the encryption, they will still collide with each others transmissions.