[HELP] rsync recursive jumps across directories

[BP25]

        Dear rsync community,

        I hope that someone can help me with this issue, probably
related to my lack of understanding of how rsync recursive works. In the
output was displayed something like this (I don't remember in the lines
below whether rsync was deleting or creating files or both, but I think
this won't matter):
--8<---------------cut here---------------start------------->8---
A/B/...

A/file1

A/B/...
--8<---------------cut here---------------end--------------->8---
In other words, the recursion did not happen linearly (according to the
tree structure of either the sender or the receiver). This is very
counter-intuitive: I'd expect that every line which lies between any two
lines of the form "A/B/..." would also have to start by "A/B/..."

        Can someone explain this, please? I would be most grateful for
any clarification. Many thanks in advance for your invaluable help.