Anyone experiencing escalation rules not firing?

We have a case escalation rule that is set up to send an email to the case assignee whenever the ticket is a specific record type, is more than 1 day old, and has a status of "New."     Our issue is that we have several cases that meet the criteria, but they have not been escalated. The Escalation Queue is also empty.  If I assign the case to another user and then immediately assign it back to the previous assignee, I then see the case in the Escalation Queue and the case is then escalated as expected.     It's possible that something is misconfigured on our side, yet it also seems like a process is "stuck."     Appreciate any insights!