Problem at Save button on Product page BO and Customization fields

[Cher]

Hello

 

I'm using Prestashop 1.7.0.6, fresh install.

If i add some custom fields on the product Options tab. it works fine. 

the custom fields are added to DB table "ps_customization_field" with an id=1 and id=2 ...etc.

 

The problem is. if you push save button again and again without any change on the product properties... or for example to  save other change on the product tabs... THE IDs of the customisation are updated to id=3, id=4...etc. on the   "ps_customization_field".

 

can some one here let me know why prestashop change IDs of customisations ??

that my problem coz the module i'm making add a new table with  id_customization_field as table key... if this ids are changed without notice, my module can't see the change... 

 

Thanks in advance for any help on this problem.

 

PS. on the Beta version of prestashop, this problem do not exist. but for production i can't use beta.