There are a few common settings for drum arps. Rather than rehash too much, I'll direct you to some information for the Montage;

https://yamahasynth.com/resources/arpeggio-making-101-montage

Note the Motif is highly related in terms of how ARPs play back - so you can look at older references as well if the newer information doesn't "sink in":

http://www.motifator.com/index.php/support/view/arpeggios_explored_part_i

.. and key modes which apply the same to both old and new generations: https://www.yamahasynth.com/resources/arpeggiator-key-modes/444-arpeggiator-key-modes

See "Fixed Note" - it describes why this is paired with drums. See how you'll want to stay away from "Direct" control for drums (generally speaking).

You'll generally want HOLD to be ON for drums so they will start playing once you press any key in the range which is set to trigger them.

Help Can't get Arp play only to work on drums .
Not sure what I'm doing wrong , when I play the Montage I can hear the drums i'm hitting on top of the drum arp thats already playing .

I just want the drums to play with out being triggered by my playing , I believe that setting is arp play only but it's not working 🙁
I have arp play only selected on the common arpeggio page of the drum kit in use on part 7 of the performance .

When the Part containing the Drum Kit is set so that the Common > "Arpeggio" > "Common" setting ARP PLAY ONLY is On (active:green), this means that when the Arp ON/OFF is Off (stopped) the keys of the Montage will not trigger the Drum Kit sounds. (That is how this works, I'm sure it is working).

This does not describe your issue, you are hearing drums from the keys while the drum Arp is running... this has nothing to do with "Arp Play Only". This is a completely different issue. The likely cause is you have the Arpeggio Velocity Threshold active at a level that provides an "accent" when you trigger the keys above the threshold velocity you have set. What you are identifying as drum sounds is probably just a Kick and Crash (accent) sounded together.

Solution: Either set the Accent Velocity Threshold to OFF or a more appropriate value.

Press [EDIT]
Press [PART SELECT x] to select the Drum Kit Part
Press the lower [COMMON] button (or touch the blue "Common" box lower left of the screen.
Touch "Arpeggio" > "Advanced"
Make an appropriate setting for Accent Velocity Threshold.