Facebook no longer posts a panoramic photo as a 360 photo

In the past, I have posted panoramic photos on Facebook, and Facebook posted them as 360 photos. Recently I have been unable to get Facebook to post any panoramic photo as a 360 photo; instead Facebook will just post it as a really wide photo. I'm using the same camera (iPhone SE) as I did before when Facebook posted them as 360 photos. This problem occurs with both the Facebook website and the Facebook app. How can I get Facebook to post panoramic photos as 360 photos?