Describe the bug
A user reported in this issue that they were seeing duplicate log entries in az webapp log tail when used on a function app. I believe the fix that the portal took in that issue needs to be taken in the CLI too. The nature of the fix is described in this comment - the logstream should be pointed specifically at the LogFiles\Application\Functions\Host directory using /api/logstream/application/functions/host.

To Reproduce
Run az webapp log tail on a function app, then execute a function.

Expected behavior
Log entries appear once.

Actual behavior
Log entries are duplicated. Example:

Workaround
Until this is fixed, you can use the provider command to force the stream to be scoped to the correct directory. e.g. --provider application/functions/host