If you are using an NSv firewall to control outbound network traffic from VMs, the appliance might get throttled if all the replication traffic passes through the NSv. We recommend creating a network service endpoint in your virtual network for "Storage" so that the replication traffic does not go to the NSv.
Note that:
1. Creating Network Service Endpoint for Storage Under Home | Virtual Networks | [Your Virtual Network].
2. Click Add and select ‘Microsoft Storage ‘ under ‘Service and Subnets should be selected as Select All and click ‘Add’.
This will re-route the storage traffic away from Sonicwall NSv firewall.