Has the query behind the Manage Delegations -> Create Delegate -> Assignment LOV changed since 21C?

Summary: I'm trying to create a Delegate for a number of people that are active and already have a delegation to someone else (those delegations were created without a problem just after 21B was deployed). Some of these people can be displayed and selected within the Assignment field to setup the delegation to someone else, but some cannot. Has something changed in 21C with the query behind the Assignment LOV?

Content (required):

Person who needs to delegate their expenses is not shown within Assignment LOV despite being active.

Version (include the version you are using, if applicable):

21C (11.13.21.07.0)

Code Snippet (add any code snippets that support your topic, if applicable):