Remove inactive Techs from search

Hi, we are currently on 12.7.8.8471-HF2 and although I suspect is by design and has always been there, our users have reported when searching for tickets Inactive techs/people who have left the organisation are being displayed in the drop-down.
Is there a way to only show the active techs whether its a custom field that links in or something else?
Im 99% this has always been there as a legacy instance we have from 2020 has this behaviour too.

Many thanks!