Creating Portfolio Performance ID fails with "The connection was reset"

[capmlbpkel]

Describe the bug
I am trying to create a Portfolio Performance ID. This fails with an error message in the browser.

To Reproduce
Steps to reproduce the behavior:

1. Go to Help -> Preferences -> API Keys / Portfolio Performance
2. Click on "Login"
3. Browser opens URL "http://localhost:49968/success"
4. Error is as follows

The connection was reset

The connection to the server was reset while the page was loading.

The site could be temporarily unavailable or too busy. Try again in a few moments.
If you are unable to load any pages, check your computer’s network connection.
If your computer or network is protected by a firewall or proxy, make sure that Firefox is permitted to access the web.

Expected behavior
Not exactly sure, probably some window to create an ID

Desktop (please complete the following information):

• OS: Debian 13 / openjdk 21.0.8
• Browser: Firefox 140.3.1esr / fresh profile
• Version: 0.80.3