Unable to trace a change in CosmosDB Activity Log

We have a terraform pipeline that manages our infrastructure, and at one point we are seeing that it has a change. We believe it moved it from backup type Periodic to Continuous (and thus is terraform plan giving us the plan to move it back).

We however do not see in our Activity Log that anyone/anything has changed it.

We would like to dive into the root cause on why this change happened.

We have a terraform pipeline run on that same environment at April 17 2026, and the above screenshot happened on April 30 2026, so we have it narrowed down to when the change happened, however there are no Activity Logs indicating the update, is there anything else we can check how this happened?

We tested that if you make the change through the UI, we are able to see in the Activity Log. (However not for the incident we are seeing)

Curious if someone can help us out finding the root cause of the change.