Created attachment 7873 
Abnormal behaviour

Hi,
I noticed that the software names are not always sorted in alphabetical order.
In the category "all" it is well sorted, but in the other ones (except favorite, where you can sort as you want).

First comes the software who were already installed at the beginning (in alphabetical order) and then the ones you install (in alphabetical order) but the do not mix. Even if you removed and reinstall the one who were originally there, the order is the same. (like you can see on 2.png)

Thanks for the amazing job !

Description: Xubuntu 18.04.1 LTS
Release: 18.04
xfce 4-12