We are running stunnel 5.56 and it has been working with no issues until November.  Since November there have been 6 short 5-15 minute outages where we see network traffic between client and server in the packet captures, but stunnel logs stop during this period.  Everything recovers on its own after this brief outage.  I am looking for help in what to look for to explain this.

Feb  2 14:49:29 *host* stunnel: LOG5[22565874]: Connection closed: 83 byte(s) sent to TLS, 74 byte(s) sent to socket
Feb  2 15:00:36 *host* stunnel: LOG6[2705685]: Peer certificate not required

We usually see dozens of messages every second, so to have an 11 minute gap in the logs is unusual.

Any help would be appreciated, thank you.