I have the issue as described above.
Config: Rpi3, Hyperbian, WS2812B 240 leds, connected to GPIO (18), powerblock powersupply (100W)
When I start up Hyperion, only the first led powers on.
Capture card works and that first led responds to what the capture card 'sees'
All leds were on once, after that I rebooted the Rpi to test again, and the problem was back.
I can't find out the problem, checked all connections over and over.
I measure almost 5V at the end of the tape, so power is good and tape is not cut somewhere.
I added the config in the attachments, it must be in there....
I hope you can help me...