Not able to order more than 100 objects list by a User attribute

Summary

When viewing Assets objects in the list view, sorting by a User attribute type does not work if a large enough number of the objects (more than 100) has an assigned value for that attribute. 

How To Replicate

1. Create an object type containing a User attribute type. 
2. Create some objects and populate the attribute with a user for the objects.
3. Change to object list view and try to sort by the User attribute.

Expected Results

The list is sorted by the User attribute.

Actual Results

When trying to sort objects in list mode by the User attribute nothing happens. Checking the console, the request returns a 504.

Workaround

There is no workaround at the moment.