Perform the following in the Azure Console:

1. Go to Azure Cache for Redis,
2. For each Redis Cache Select Firewall.
3. Delete any Rule that has 0.0.0.0 in it’s start and end ip address.
4. Select Save.

Default Values:
No firewalls rules are set

References:

1. https://docs.microsoft.com/en-us/azure/redis-cache/cache-configure#firewall