I have the same problem.

Running :

from databricks.sdk import WorkspaceClient
w = WorkspaceClient()
w.dbutils.fs.ls("abfss://xxx@yyy.dfs.core.windows.net/zzz")

via Databricks Connect gives the same result as running :

from databricks.sdk import WorkspaceClient
w = WorkspaceClient()
w.dbutils.fs.ls("/")

The problem seems to be the presence of '//': in that case the string being passed to the databricks library seems to be just '/'

When doing the same directly on a normal Databricks Workspace Notebook it works:

dbutils.fs.ls("abfss://xxx@yyy.dfs.core.windows.net/zzz")