Good day Damiam
Yes, in 2.10 the reference code was added to the Related Descriptions link labels via apps/qubit/modules/informationobject/templates/_relatedMaterialDescriptions.php. It prepends $item->object->referenceCode (and $item->subject->referenceCode for the reverse relation).
To remove it upgrade-safely, override that template in your theme (plugins/<yourTheme>/modules/informationobject/templates/_relatedMaterialDescriptions.php) and delete the two lines that set $itemTitle = "{...referenceCode} {$itemTitle}".
Leave the rest to keep level-of-description + title, or drop those lines too to show just the title as older versions did.
Clear the cache (php symfony cc) after.
Regards
Dr. Johan Pieterse
The Archive and Heritage digital Commons Group