5V TTL signals over 4m or so?
Please read https://learn.adafruit.com/adafruit-neopixel-uberguide/best-practices  If you've already read it, read it again and do what it says this time.

You are violating best practices in at least 3 ways. 

1 - You don't show a capacitor on your Murata output.

2 - You don't have a resistor on your data line.

3 - You are running long cables.

Try something like this:







simulate this circuit &ndash; Schematic created using CircuitLab

Note that the twisted pair can be almost any guage - 26 will do fine.