Pages erased when ordering them

Hi everyone,

I'm facing big issues when trying to change the pages order in the admin (using the section "ordering" in the "advanced" tab). Here is what I do :
I drag the pages to the place I chose, and the re-ordering seems to work fine (even if sometimes the prefixes are odd, starting from 2 for example, or jumping from 2 to 4). Then I save the modifications, and quite often whether 1) there is an error message saying that the page cannot be found, or 2) the page I've moved is duplicated... and when I leave the page's editor mode, it has been erased.

Sometimes it's working fine, sometimes there's a problem, but not always in the same way... I cannot see any logic here.

I point out that I haven't made weird modifications that would generate this problem, and that it's happening on several sites, including one using the theme "learn2" which I'm currently using "out of the box".

I cannot imagine I'm the only one facing this issue... does someone already had (and fixed?) the same problem?

Thanks

@jordan, Are you, or have you been, using folder names with capitals (or maybe diacritics)?

Usually, nothing gets deleted - check if the folders are still existing and what name they have. Also, change as mentioned already all folder names to be small letters and no special letters. letters, numbers hyphens - best actually let it create automatically from the title field.