Help locating clicking noise?

I'm having trouble finding this noise. I'm hoping someone recognises it.

Here's what I've learned
– it happens when pedaling or coasting
– it seems more pronounced when sitting (more weight on the rear wheel)
– it's not consistent – I feel like it's often 2-3 clicks where there could be 4 (so some are skipped).
– it seemed more pronounced turning left instead of right. With straight about in the middle, noise-wise.
– no noise when just spinning the wheel off the ground (IE no weight)

I can't see anything obvious and haven't been able to replicate when I'm off the bike.

Have you heard this before?

Sorry for the filming!