• if you have private link please check that you have it both for dfs and blob for the same resource,
• please check dns which you are using with nslookup, popular error is that someone add private link with private link dns but normal address should be used,
• application used for mount need to have IAM role ""Storage Blob Data Contributor" to aceess your ADLS (Azure: App registrations then you add it IAM role in ADLS IAM)
• please unmount and mount again
• example code to mount:

configs = {"fs.azure.account.auth.type": "OAuth",
           "fs.azure.account.oauth.provider.type": "org.apache.hadoop.fs.azurebfs.oauth2.ClientCredsTokenProvider",
           "fs.azure.account.oauth2.client.id": "your_app_client_id",
           "fs.azure.account.oauth2.client.secret": "your_app_client_secret",
           "fs.azure.account.oauth2.client.endpoint": "https://login.microsoftonline.com/your_tenant/oauth2/token"}
 
dbutils.fs.mount(
  source = "abfss://container@storage_account.dfs.core.windows.net/",
  mount_point = "/mnt/your_folder",
  extra_configs = configs)