increase total ledcount to 120 leds. Make sure there aren't any leds skipped in the led frame layout.
Hyperion can't steer and address leds that aren't there at the end, so you know for sure that every led will be addressed.
If that doesn't help maybe it's a hardware fault in the strip between led 101 and 102, that's why leds lite up suddenly that didnt before when swapped around.
Wiggle the strip between that point 👉 and maybe they come alive.
I had the same thing, my last" xx leds weren't illuminated, fixed it by soldering the "joint
I know nothing of Adalight protocols and Arduino so hope this steers you somehow in right direction ➡️