Failed to register App when running from local due to SSL error

This seems to be related to SSL Error while installing addon - #5 by piotr.patrzek1. But that thread said it was solved and it did not include the client-side error. So I created this new topic.

When I use the official Atlassian Connect Express to register an APP, there is a big chance (> 50%) that it errors out with the following error (note the highlighted subcode: ump.pluginInstall.error.ssl line):

Failed to register with host (200)


Add-on not registered; no compatible hosts detected

It normally works if I kill it and rerun. I am using cloudflare’s argo tunnel to expose my local service. ( Argo Tunnel | Secure Tunneling Software | Cloudflare). I used this command to start the local service: AC_LOCAL_BASE_URL= node -r esm app.js, where is my public hosting name.

I have no idea what I should check as it is not 100% reproducible. Can someone please help?

By the way, when I install it manually from the ump page, I also see this error often.