Steps to reproduce

1/ create a theme named "test" (respecting lowercase !). It could a copy of another theme
2/ give permission to this theme to a user
3/ rename theme "test" as "Test" (take care to the case !).
4/ return to user and look at permission to the theme : the theme is listed (with new name) but box is unchecked.
5/ check the box and save
6/ return to user and look at permission to the theme : the box is unchecked.
7/ retries give same result.

Expected result

1/ after renaming the theme, I thought that permission was kept for users to this theme (box checked)
2/ eventually, if I had to check box and save that this operation was not be lost.

Actual result

1/ I can spend hours to check box to give permission to the theme for a user and save when I return to permission box is always unchecked