Hi: it actually looks to me like it is behaving as expected. Photo view arranges the tiles in order to make best use of space – so it’s important to note that as part of that they are not rigidly laid out in a fixed, linear style grid and some amount of flexibility exists.
This illustration might help to explain things: note how the fourth event in sequence appears as if after the fifth, if you try to interpret it as being ordered in rows running left to right, top to bottom. However, the subtle difference is that the fourth event in that example starts at a higher position than the fifth and, in this context, that is the correct placement.
I do appreciate it can be slightly unusual if you weren’t expecting this – but does that at least clarify things?