Audit trail is not showing some actions sometimes

It has been observer that for an item, its name was changed from for eg. “X” to “XY”. This is being reflected in one of the Sales Order. Again the item name has been reset to “X” from “XY”. This renaming activity has not been logged in the audit trail but the activity can be referred from the Sales Order created at that moment.

The same kind of issue was observed in a “Payment Entry” record wherein a user canceled the approved record but it was not logged in the audit trail.

Does anyone here has observed the same kind of behavior?