Some German characters are malformed in Customer Notifications

Issue Summary

Certain characters in Jira Service Desk customer notifications show incorrectly in the notification email, but not the template editor. This happens when the language is set to German, but not when set to English (in English, the characters are rendered correctly).

Steps to Reproduce

1. Set instance or project language to German
2. Have a customer notification (e.g., customer invited) with certain characters (e.g., ü or ß)
3. Observe (via the emailed notification) that the characters show as ü or ß

Expected Results

ü shows as ü in the emailed customer notification and ß shows as ß in the customer notification.

Actual Results

ü shows as ü and ß shows as ß.

Workaround

Currently there is no known workaround for this behavior. A workaround will be added here when available.