Your problem is most likely a new problem as of today. There are already a couple other threads. I’ll leave this one open in case people need to ask something about the incident:
Otherwise, I’m going to suggest this thread has already wandered a bit. While the general troubleshooting steps here are good, I don’t think we ever pinned down a specific problem with a specific solution; hence, I’m going to lock this thread and encourage the community to open new topics for new problems with Forge tunneling.
Edit: The docs mean what they say. I was wrong about the ngrok aspect see my subsequent correction
Maybe one last “pro tip”… A fundamental workaround is to switch to the native Node.js runtime because, as the docs explain:
The new native Node.js runtime no longer requires a local Docker image for invoking your Forge functions locally. This simplifies the local toolchain for setting up the tunnel, and will improve the performance of your tunnel.
When the runtime leaves preview and becomes GA, I would say this won’t even be a “workaround”. But, during preview, please be aware the new runtime does have some differences and known limitations.