"Guest User" - Maybe a Bug ?

I Have define a user 'ticket' such as guest user, to have access only to "ticket simple" and Allocated it as "ressources" on only 2 projects.

Those 2 projects are linked both to one different product which as only one version.

THen I try to create a ticket.
- When I didn't select anything or the first project on the list, the origin product version linked is correct (IMAGE _1)

But as soon as I select the second project, the origin product version is mesed up and it shows ALL the active versions of ALL the product defined, including those without any link to this project !

oO quite strange.

Any Idea ?
Thx