Failed to install connect app through JSON descriptor link

When I try to upload my connect app using the link to the atlassian-connect JSON file I get the error: “The app failed to install. Please try again later or contact the app vendor.”

In the network tab, the only request that I see fail after attempting the install is a POST to https://{{my jira org}}{{token}}, which returns with a 500 error.

The connect app is hosted within my Angular project. When I was developing the app and testing locally, using the atlassian-connect-express npm package and ngrok to host it, everything worked fine. I didn’t need to manually upload the app during development, I just provided my JIRA credentials and the package would handle hosting the Angular ngrok server, and installing/updating the app when I made changes. Now we are hosting the app in one of our environments and need to be able to install the app using a link. Here is what my atlassian-connect.json file looks like (I have replaced specific names/urls with generic ones, but I can confirm the real links we are using are accessible and I can access the JSON file in the browser):

I have ran the file through the Atlassian JSON app descriptor validator and it passed with no issues, and I was using the same JSON file for local development, except all the “” links were replaced with “{{localBaseUrl}}”. My assumption is the atlassian-connect-express package would automatically replace the handlebars with the ngrok link it generated every time I restarted the Angular app. For local development this all worked (although like I mentioned it installed/updated the app automatically in my JIRA org), so I’m just struggling trying to figure out what is wrong. The JIRA application install audit logs don’t really give me any helpful information and just say “Failed to update app plugin.13248870104165452919.atlassian-connect.json (atlassian-connect.json)”, and I can only find generic advice online, of which I’ve tried a couple “solutions” to no avail (making small changes to the content of the JSON descriptor).

Any suggestions on how to solve this issue, or where to look to troubleshoot/debug better, would be greatly appreciated.