Issue templates with `(` inside are not loading

Summary

trying to apply an issue template where the issue template name includes a ( and ) is longer (in my case 1109 bytes) leads to endless loading and not applying the issue template at all. a issue name without this characters smaller template (in my case 440 bytes) works without problem.

chromium:

waterfox classic:

Steps to reproduce

• create an issue template name with a ( and ) in the name like Delete Server (Project) at least 1109 bytes in size
• create a new issue
• choose your newly created template
• watch the loading spinner

What is the current bug behavior?

issue template not applied

What is the expected correct behavior?

issue template applied

Workaround

remove the ( and ) from the issue template filename

Output of checks

This bug happens on GitLab.com

tested on

• win, waterfox
• win, chromium
• macos, ? (collegue of mine had the same problem, don't know his browser)