@akdrone ,looking at the position, and fitment of the battery, it appears to be quite exposed ,within the frame of the drone body ,compared to inside on other drones ,maybe this could have been a contributing factor
@its a well known fact that a cold battery ,will reduce the cells capabilities, to allow the normal chemical process to take place ,as they discharge ,which in turn reduces their power output ,when a high current flow is required ,such as...
Perhaps if you could post the data, someone might be able to find the cause.
But without being able to see the data which contains much, much more than you've explained, it's just not possible.