App Fails to Enable in Jira Cloud After Marketplace Installation

Hello.
I built a Jira Cloud app using Atlassian Connect, and I’m developing locally using ngrok. Everything works fine in dev mode. However, when I install the app from the Marketplace, it is not enabled by default. When I try to enable it from the “Manage Apps” screen, I get the following error: “This app failed to enable. Contact the app vendor for support.”

Here’s what I’ve tried so far:

  1. I installed other apps to check if the issue is specific to my app, and they work fine.
  2. I used the production descriptor file to manually install the app using the Universal Plugin Manager (UPM), but I get the same errors in the console, with the installation loading infinitely

Here are the browser console errors I’ve encountered:

  1. A POST request to the Jira instance returns a 500 error:
POST https://<your-instance>.atlassian.net/rest/plugins/1.0/?token=<REMOVED-TOKEN> 500

  1. Multiple POST requests to Sentry are blocked by the client
    net::ERR_BLOCKED_BY_CLIENT

The app used to work fine previously, and I’m not sure what has changed. I’m unable to diagnose the problem and need your help. Thanks in advance!