Hello. Thank you for contacting the Toolset support.
Can you please tell me on what section of the reference link you shared you want to display the child category. Dose child category is assigned to that product?
Maybe few screenshot of backend as well as from frontend will help us to guide you in the right direction.
In addition to that - I see you do not update the Toolset plugins to it's latest official release version. We always recommend to run you sites with latest Toolset plugin version.
Let me review how many products are assigned to the child term first.
Can you please share admin access details.
*** Please make a FULL BACKUP of your database and website.***
I would also eventually need to request temporary access (WP-Admin and FTP) to your site. Preferably to a test site where the problem has been replicated if possible in order to be of better help and check if some configurations might need to be changed.
I have set the next reply to private which means only you and I have access to it.
I see you have the following page with the slug "produits":
=> hidden link
- hidden link
I see you had content template with the same slug (I changed the slug however):
- hidden link
WordPress require unique slug site wide for post types, posts, pages, terms etc..etc..
Can you please confirm you are using unique slug sitewise and also check with minimum installation to ensure there is no conflict with any third-party plugin or theme.
Please disable the cache plugin and save the permalinks once from Settings -> Permalink and then try to check if you able to resolve the issue.