DM = Dialog Module. In this case we have experienced the problem on various DMs, and another co-worker of mine has also posted a question about the same problem.
https://www.devconnectprogram.com/forums/posts/list/0/24484.page#p162658

Several calls each day are experiencing a long delay inside a DM. The call enters the DM and the announcement plays correctly. The DM is expecting a response from the caller within 5 seconds, but these calls are stuck in the DM for over 40 seconds.

We do not see errors in the EPM server related to these calls which makes troubleshooting the problem a challenge.