Agent remains "on call"/"Unavailable" after warm transfer to external number

This seems to be different than the topic regarding Live Report status after a warm transfer from several years back.

Users report performing a warm transfer to an external number as is their normal workflow, but only in the last few weeks has it occasionally left them “unavailable” and prevented them from receiving more calls until they notice they’re still unavailable. 

My understanding is that the Live Reports sometimes still shows them as “on a call”, but the user’s application always shows them as “On a call” until they manually make themselves available again.