When swapping out your Sonicwall Gen6 for a newer Gen7 the config needs to be converted,- unless you want to start from scratch. Sonicwall has provided a nice migration utility for this, available here: https://migratetool.global.sonicwall.com/
Troubleshooting public DNS replication
Sometimes we might run into a DNS replication problem in the public domain. This might be because of a DNSSec issue