Rhythmic clicking, new bike

Hi all,

Bought a Ribble CGR with Shimano 105 groupset back in Feb. Had a few outings, maybe 650km total. Recently it's started making a rhythmic clicking sound (began with 1 click, is now 2, as per video), when the left pedal reaches ~12o'clock.

The click does not occurr when I turn the pedals with the bike suspended, only when weight/force is applied. The click also occurs when I'm stood up on the pedals (i.e. I don't think it's the seat post). Lastly, the clicks happen on both chain rings and on each gear; they also speed up in time when I pedal faster.

I know random clicks are a nightmare to diagnose, but does anyone have any suggestions where I should start? Bike seems a bit new to be having BB troubles…

Many thanks in advance.