Categories order issue & 1 missing

[Xanarkan]

Hello, 

First of all here is some information to get you started, just to save time.

Installation type : new default install performed by the 1-click module from OVH.
PrestaShop version : 1.7.6.0
URL : https://retrokai.store
Theme : defaut
Code : original
Hosting : OVH Web Hosting "perso"
PHP : 7.3.6 -> downgraded to 7.2.19 cuz' PrestaShop 1.7.6.0 isn't compatible with PHP 7.3
MySQL : 5.6.43-log
Browser with the issue : all

The site is brand new by default. No module installed, no modification in the code. The only thing that was done was the change of the visuals and the addition of product.

And yet, I have a problem in the order of my primary categories. As you can see on the screenshots: in the back office they are in a particular order that I have chosen. In the front end, they do not appear in the same order, and even worse... a category is missing.

If someone has a solution to this problem for which I have already done a lot of research, I'll take it.

Thank you in advance.

Edited October 31, 2019 by Xanarkan
PHP version (see edit history)