What means 'Reentrancy Found' in the log, is it harmless, and what can be done to prevent it?

Summary:

What means 'Reentrancy Found' in the log, is it harmless, and what can be done to prevent it?

Content (required):

We noticed occurrences of "Reentrancy Found" in our system logs, and wondered what caused this and what can be done to prevent it. From the log it says it skips reentry, so it appears to be harmless.

Version (include the version you are using, if applicable):

Cloud

Code Snippet (add any code snippets that support your topic, if applicable):

2021-11-25 11:36:15.913 1720250 Debug Agent Agent TMS.SHIPMENT_CREATED reentrancy found, reentry 1 times, agent reentrancy level type is SKIP ON REENTRANCY reentrancyLevel: 0 [lifetime - 2]