Version

I am using the following packages

botbuilder-schema==4.13.0
botbuilder-core==4.13.0
botbuilder-dialogs==4.13.0

Describe the bug

ShowTypingMiddleware goes into an infinite loop of sending typing activity to user when on_error() method of the BotFrameworkAdapter is called. It doesn't stop till the application is restarted. This is easily reproduced in BotBuilder-Samples tested with BotFramework Emulator.

To Reproduce

Steps to reproduce the behavior:

1. add ADAPTER.use(ShowTypingMiddleware(delay=0.5, period=1.0)) to app.py of 13, Core Bot Python Sample
2. Write some code that takes calls the adapter's on_error() method i.e. print(ThisIsABug) in destination step in dialogs/booking_dialog.py
3. Start the app and test the dialog from BotFramework Emulator.
4. The app sends infinite typing activity to the emulator when the error is encountered in code.

Expected behavior

ShowTypingMiddleware should stop sending typing activity if on_error() method is called.

Screenshots

Additional context

NA