ESP-32 WS2812b flickering when lost Wifi connection

[Adding]

Hello everybody,

today I noticed a weird flickering behaviour of a WS2812b LED strip, which is controlled by an ESP-32 Wroom 32D. The flickering ONLY occurs, when Wifi connection is lost and the flickering stops (everything works fine) when the ESP reconnects to the internet. I made my own circuit board with all the design rules I found in the internet.
Here the important setup:

1. ESP32 Wroom 32D (see picture for schematics)
2. WS2812b
3. NeoPixel library from Adafruit
4. WifiMager library

Like I said, the flickering behaviour only occurs, as soon as the internet connection is lost (some random LEDs light up in a random color for a very short time, which repeats over random time spans). When reconnected to the internet, the LEDs are working perfectly! I am still pretty new to this topic (my first project with ESP32) and I don't know whether this is a problem in Code (maybe NeoPixel library?) or a problem in my hardware setup (but apart from the described problem, everything works fine).

I appreciate your help, thank you very much!

[Charles_Wen]

The power supply may be insufficient, when WIFI disconnect, the board need more power, then the strip flicker.