Custom URL using non-Latin characters prevents item page rendering, triggers repeated `/server/api` requests

[MMilosz]

Describe the bug

When dspace.customurl contains non-Latin characters (e.g., Cyrilic or Arabic), the item page fails to load in the UI and remains in an infinite loading state. The browser repeatedly triggers requests to /server/api.

This bug can be recreated in sandbox.dspace.org, as well as in localhost.

If the custom URL does not exist, the UI correctly routes to the /404 page.

The /server/api/core/items/search/findByCustomURL?q=NON-LATIN-CHARACTERS responses themselves appear valid and return successful results.

To Reproduce

1. Create or edit an Item.
2. Set dspace.customurl using non-Latin characters. For example, type الصحراء (Sahara) or снеговик (snowman).
3. Save and/or deposit the Item.
4. Attempt to access the Item using its custom URL, e.g. https://sandbox.dspace.org/items/الصحراء
5. Observe the UI behavior: infinite loading state and repeated /server/api requests in the browser network tab.

Expected behavior

The item page should load successfully when accessed via a custom URL containing non-Latin characters.

Related work

• Caused by [DSpace-CRIS] Creation of a custom URL for Items (Frontend) #4814

[MMilosz]

The item can still be accessed by administrators using its UUID, by navigating to the UUID-based route and appending /edit/status (e.g. /entities/<type>/<uuid>/edit or /items/<uuid>/edit).

However, non-admin users cannot access the item in any way via the UI. The item still renders correctly in search and browse views (e.g. /search)