OSM basemap tiles blocked due to missing HTTP Referer header (post-Sept 2025 policy)

[juanluisrp]

Describe the bug
OSM tiles from tile.openstreetmap.org display "Access Blocked" errors in the map viewer. Some tiles show missing Referer header in tile requests, violating OSM's Tile Usage Policy.

To Reproduce
Steps to reproduce the behavior:

1. Go to Map
2. Click on Layers and Select OSM as base layer.

Expected Behavior
The default OpenStreetMap (OSM) basemap loads correctly in the GeoNetwork map viewer without "Access Blocked" tiles.

Screenshots

[juanluisrp]

This issue has been fixed in OpenStreetMap already openlayers/openlayers#17089.