Do latest release 5.3 for Mac OS have a bug with second level dialog items?

I have a dialog configured as:

1. Dialog Phrase 1 (configured to Stay at same dialog level)

2. Dialog Phrase 2 (configured to Stay at same dialog level)

   2.1 Sub dialog phrase 2.1 (configured to switch to previous dialog level)

   2.2 Sub dialog phrase 2.2 (configured to switch to previous dialog level)

3. Dialog Phrase 3 (configured to Stay at same dialog level)

   2.1 Sub dialog phrase 3.1 (configured to exit dialog afterwards)

   2.2 Sub dialog phrase 3.2 (configured to exit dialog afterwards)

During game, if I select Dialog Phrase 2 I can see my character talking. All the eventually related Dialog Part Actions are correctly executed. But when it is supposed to read on the screen the list containing Sub dialog phrase 2.1 and Sub dialog phrase 2.2, I always read Dialog Phrase 1 and Dialog Phrase 2, instead.

The same dialog with Visionaire studio version 5.2.1 (build 1235) works perfectly.