Just tested with your images, everything fine here.
Watching your video rang a bell, though, I remembered having a very similar issue back then when I first tested my LED strip but was using a power supply with too low power rating. If I raised the LED brightness beyond a certain point the strip would just shut off completely. This was most easily to reproduce with white light (as this means all three R/G/B LEDs are active at the same time).
Not sure why that also happens with green and why it was OK on the RPi3, but as it's rather easy to test and would provide some interesting datapoint please give it a try:
Start up hypercon, connect to libreelec and then pick white on the color-wheel. Then change the brightness (on the vertical slider to the right) and check if the LEDs turn black at some point. Checking with other colors (yellow, green etc) may also be interesting.
so long,
Hias