No, the metronome isn’t connected to the H90 at all.  Each device (metronome & H90) is using its own clock.

EDIT:  to be clear, this isn’t a case where the metronome and H90 clocks are ever so slightly off and the discrepancy between them gradually grows.  It happens almost immediately, and even if you turned off the metronome, the timing issues would still be clearly audible.