I brought this up with support and they said there was an issue that needed to be reported here to get resolved.
At the moment, the system is configured in such a way that once an incoming call is warm or blind transferred to another party, and that party does not answer or rejects the call, the original agent is unable to return to the call. The caller remains on hold, and there is currently no functionality to take them off hold and resume the conversation without ending the call. The hold button is highlighted, but there is no way to resume the call. This is a huge problem for any company taking inbound calls.
I've included the loom video link as well.