Problem with loop on Cisco Nexus 3524-X

[MassiveGRID]

Hello, 

I'm having issues with loops on Cisco Nexus 3524-X connected with Ubiquiti Devices and Meraki Devices. 

The topology is somewhat complex, so I will try to be as thorough as possible. 

Have two Cisco Nexus 3524-X stacked ( vPc ).

One Port channel ( Ports 31 on both Nexus switches ) , trunked connected to Ubiquiti Core switch. 

Single Port 29 connection from Nexus-1 to Ubiquiti Firewall ( trunk allowed vlan 9 ) for the uplink of Ubiquiti public network )

Port Channel 33 is the uplink to Cisco Meraki ( access on vlan 1 ) .

Port channel 34 is the connection to Meraki LAN network ( trunk allowed vlans 2-1600 )

Port Channels 2-5 are trunked to a Proxmox Server Cluster. 

Port Ethernet 1/45 is the link to our ISP.

The problem is when connecting to the Ubiquiti network, a loop happens and it brings all network down ( Ubuquiti + Meraki + Cluster ). 

I'm trying to understand where is the loop(s) happening and how to solve them. 

Any help would be highly appreciated. 

I am attaching configuration of the two Nexus switches plus the logs I've gathered from the loops. 

[balaji.bandi]

This look for me some mac address flapping between ports.

check what meraki side what is spanning tree configured. make sure you configure meraki higher spanning tree priority.

other test you can for testing  remove meraki device from network and connect ubiquit router  and see if this issue persists ?

[MassiveGRID]

Thanks for the response. I will check into it and update as necessary.