Self-hosted (docker + Windows IIS) authentication problem

[EdwinChua]

Instance Type (hosted/ docker/ other):

Docker

Steps to reproduce issue:

• I troubleshooted this issue
• Successfully found my [test] Google Action in Google Home
• When I selected my Google Action, I was brought to my self-hosted gBridge instance, and authentication was a success (I think?)
• Was redirected to https://<SITE-URL>/r/<GOOGLE-PROJECT-NAME>#access_token=<REDACTED>&token_type=bearer&state=<etc...>
• At this point, my web server returned an error "The resource you are looking for has been removed, had its name changed, or is temporarily unavailable."

Expected behaviour:

Successful authentication, browser closes, and Google Home lets me configure devices

Actual behaviour:
Receives error message: "The resource you are looking for has been removed, had its name changed, or is temporarily unavailable."

Additional info:
I am using Windows IIS v10.0.18362.1. It is likely to be a configuration error on my part, but I can't figure out where could be the problem.

Thank you for your time!