Power injection works, but doesn't work well

Issues
1

TDLR: I have about 10 meters of 22GA coming from the power supply directly to a second LED strip for power injection. The problem is that there’s voltage drop immediately: it starts as yellow and goes into red and then dims into nothing in about 30 LED’s (the color is set as light green). It’s getting power directly from the power supply; how can only so few LED’s be lit up?

Before I spend a whole day trouble shooting or spending money on things, I may not need I was hoping for advice in which direction I should go. The problem is stated in the TDLR. My first strip of LED’s (~2-3 meters) is lighting up just fine. At the end of my first LED strip the data wire joins up with the power injection wire and follows it to the 2nd LED strip where the problem is occurring.

Could the issue be the distance / size of the data wire? The distance / size of the power injection wires? Poor material quality of wires? Poor soldering job / too many soldering jobs (Made a couple of mistakes with length.)? Wago connectors?
Farther fetched idea: Bad power supply?

Specs:
Power Supply - MEAN WELL LRS-200-5 200W 5V 40 Amp Single Output
Wires - All 22GA
LED’s - WS2812B 5V 60 LED/m
Microcontroller - Esp32

Here’s a diagram.

The green lines here is the first LED strip and the blue is the 2nd LED strip / where the light cuts out. The power injection cable follows the green line and hugs the wall all the way around until it gets to the second strip.

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2

You are asking a lot of the data wire from the end of the 1st strip to the start of the 2nd, that’s on the long side for a data wire (any data wire).

The bigger issue is your injection line.

Your strips are 60 LEDs/m guessing .3W/LED at max brightness gives 18W/m of strip (max).
Guessing your end strip is 2m(?) gives 36W or at 5V that’s a little better than 7A (max).

Refer to one of the voltage drop calculators: Voltage Drop Calculator
Plug in 10m at 5V and 7A for 22AWG wire and you get?

A voltage drop of 7.47V or 147% of 5V or you won’t get anything at the LEDs it’s all lost as heat in the wire.
But, you say I don’t need max brightness, 50% will do fine!
Plug in for 3.5A and get ->3.7V drop, so a whopping 1.3V actually gets to the LED’s
Go to 25% brightness, 1.75A → 1.85V drop leaving only 3.15V for the strip.

You’re asking your injection ling to carry too much load over too long a distance with too small a wire.
22AWG is fine for data, but is not suitable for the kind of current you’re asking it to carry.

You may still need to deal with the length of your final data line (I always suggest a TxRx differential pair at 10m), but realistically until you deal with the power issue data is moot anyways.

BTW, your power supply is likely just fine.

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