This should be handled with a deviation/CAPA. Possible run log mean temperature calculations. Perform an impact assessment. Figure out how to correct it, and how to avoid it again. Review the Qualifications to see history. Review the continual monitoring to see if there was a gradual trend or a single event.
Some corrections might be (1) better PM on the stability chamber (2) Tighter alerts so that you see a OOS well before it goes from “alert” to “alarm” (3) Review of an “excurtion time, or alarm delay” - was this due to an open door event, but really the chamber didn’t change temperature, just a pocket around the open door (4) Install curtains in the doorway to keep airflow down during an open door event.