This photo of the sun behind a cloud was taken on the south coast of England in early May 2021 using an iPhone 11. A halo is visible which I think is the 22-degree halo. However, the photo also shows a small, pale blue dot near the middle of the photo, within the photo, left and above the Sun. Please could somebody suggest what the blue dot is?
Yes, I believe this is the internal lens reflection. Lens reflections have hexagonal shape, and if you look closely, it somewhat resembles this shape. Also, see other answers in the comments.
Internal lens reflection happens because the lenses don't have 100% transmission. This often happens when taking bright objects, like Sun in your example.