Hello, issue with flicker, read that it’s important to have same GND but don’t understand in detail, not enough with same group in electric central? Here I done some wiring, first one is how it looks for the moment then some idea from my side. I use rs485 TTL for long signal distance below 10m. strip one 5m and strip two 5m. Green=signal. Hope someone here can help me soon 
Pictures in wrong order, using “1“ now. ESP 32.
need common ground
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Thanks for answer, I will try:
More info:
Multiple power supplies
When doing power injection with multiple power supplies never mix two power supplies on the same LED strip. You can connect grounds together, just never the positive rails. This means you need to segment your LEDs based on power supplies, including your power injection. For the same reasons listed below, never connect multiple power supplies to the same strip for power injection purposes, always fork one power supply and route it to the start/mid/end of the same strip.
Because multiple power supplies could have subtle variations in their positive voltages (e.g. 12.1V and 12.3V), this could lead to power flowing in ways that aren’t expected or which could be damaging to your equipment. In general, wired power supplies don’t like to be directly connected to other power supplies unless they are explicitly designed for that purpose. This is not true for cell batteries, which are usually fine with being connected in parallel provided all the battery voltage + chemistry are the same.
If many power sources are used (for example separate one for ESP and separate one for the LED strip), then all their grounds (GND, V-) must be connected together (but do not connect their V+ together!).
Example