You configured a connection to Azure and some storages are not appearing under Storage tab, even after manual sync.
CloudSOC
Additional hardening is applied to storage account which blocks external connection. CloudSOC IP ranges needs to be allowed on the storage so we can access it for IaaS capabilities.
On Azure Portal, go to your storage account, then to Security + networking > Networking section, and add the below IP ranges under Firewall section:
192.19.243.250
148.64.0.0/20
144.49.240.0/20
144.49.128.0/20