Any idea what this sound is? Had drive train cleaned and lubed 2 months ago.

How many miles on bike? I know right after I built my bike up I got a little squeaking in BB like rubber on rubber noise when it was slightly wet. Went away after a 100 miles or so and is haven’t heard it since.

Sounds dry and dirty to me.

Chain is dry. 2 months between lubes is waaay too long. Clean and lube every couple of rides, every ride if it’s wet and muddy.