Can't access external Function App after it was linked and unlinked from the Static Web App

**Describe the bug**

The Function App could not be accessed (return 401 Unauthorized) after it was linked and even after unlinked to my Static Web App. I have checked the setting of the Function App after unlink and found out that the authentication setting hasn't been cleared. I have tried to clear the setting manually but the issue is not resolved.

**To Reproduce**
Steps to reproduce the behavior:
1. Create a new Function App
2. Deploy and access the HTTP trigger function using the Function App's URL. The function can now be accessed normally using the Function App's URL
3. Link the Function App to the Static Web App. Now the original Function App's URL can't be accessed which is expected but the API can't also be access from the /api/... which is not expected (the api_location field in the Github's Action config file has been cleared to empty string)
4. Unlink the Function App
5. The Function App still couldn't be accessed using the Function App's URL

**Expected behavior**
1. Function App should be accessible using /api/...
2. Function App should be accessible again after being unlinked from the Static Web App

**Screenshots**
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**Device info (if applicable):**
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**Additional context**
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