Disturbing: Litchi panorama. Every eighth pic is our of focus...

[GP-Mavic]

While reviewing the last two panoramas I shot (34 pics, 4 rows of 8. I know that doesn't add up.) I noticed that #8, #16 and #26 photos were greatly out of focus, both times. I recently re-calibrated my gimbal as the horizon was a couple of degrees off. Started right after that. Any thoughts?

 

[Egika]

Can you show those pics? Is there probably just sky or another low contrast surface in the center of the frame where the camera don't know where to focus on?