Half Strip goes out

New to using WLED and ESP8266 for running a couple ws2811 12v pixel lights. I have a small set up of 2 separate strings of 50 Led pixels. Originally had them wired with Cat5 cable as I had a bunch laying around. Hooked up via Sacrificial pixels for level shifters.

I have them going down my railings at on my porch. The controller is on one side of the porch. The side closest to the controller works fine, the other side was working fine with Cat 5 cable, but when switched to 18/3 it stopped working correctly. Only half the lights will light up and the rest flicker. I’m not sure what I am doing wrong. Could the 18/3 be causing interference on the data line? Is there any way to solve it without having to run a seperate data line?

Thanks for all your help in advance!

Sounds like a garden variety bad connection.

Thats what I thought aswell. So I replaced the connectors on both ends. Did not make a difference. I looked for voltage drop as well. 12.3v going in, 11.9v coming out. Also tested the cable resistance for issues. 0.3 ohms on all 3 cables. Which seems okay for 18 foot of cable.