Drivetrain noise

Hi all,
I recently deep cleaned and waxed all of the components of both of my bikes. I have a OCR 3 (pictured) and a trek checkpoint.

I have a few questions-
1- is this an acceptable level of noise for a newly waxed chain? The chain is a HG701 installed the correct direction.
2- what is the “rumble” noise in the longest gear from. My checkpoint also makes the rumble noise in this gear, even when using wet lube.
3- I was told a mismatch of age on the compenents could cause the rumble, but the chain is under .5 wear and the chainring and cassette seems to be in good condition.

Thanks in advance for any insight.

Drivetrain noise
byu/usuhockey inbikewrench

by usuhockey