When you say drop off - how are you observing this? Loss of ping?
Is this loss of connectivity permanent or intermittent? Does the loss of connectivity happen immediately after connecting the Meraki switch to the network, or does it happen 30s or 90s later?
The Meraki switches are not doing active discovery (aka sending traffic). They passively listen to the traffic they see. So it is impossible for this feature to cause a client to drop off.
HOWEVER, this doesn't mean they couldn't cause a client to drop off - it just won't be passive client monitoring.
Things I would check for:
- IP address conflicts. Perhaps the Meraki switch is using the address of something else on the network?
- Spanning tree issues. Are there are redundant layer 2 loops? If you have multiple brands of switches strongly consider configuring the other switches to use MST with a single default region to make sure you are not having spanning-tree issues. Make sure you have configured your core switch as the spanning-tree root guard.
- Do any of the switches have any security features configured, like spanning-tree guard, etc?
- What do the other switch logs say?
- What does the Meraki switch even log say?