This has happened to me too. When the bracelets are worn loose and they are just at the right angle, this can happen.
It would not happen on a tighter fit. However, I don’t like the tight fit.
Does this just happen to your small and classic (that’s the combo I have & it’s happened)?
Has this happened with your two classics before? If I remember correctly, I think it also happens with the classics. I recall reading that a user, who has two classics, stated her two bracelets switch places as well.
Omg yes my two classic Loves did this for the first time EVER when I was showering the other day and could not believe they actually crossed over one another! Mine are a loose fit too (15-15.25 cm with 17 Loves).