how the same instrument can have different sound on each beat traverse?

[sam]

Hi,
Why the same instrument sounds differently when the pattern is traversed the first time vs the second time?
there is no motion or other coarse/tunes changes.
the sound is "FM Metallic HH2". audio is attached.

thank you.
sam

[sam]

I believe this is caused by the LFO Depth, I have noticed it on another instrument.

sam