In many multiselect pop-ups (where multiple values can be chosen), the chosen values aren't disabled and checked. This can be really frustrating when a lot of values have been selected.

Expected:
Already chosen values are checked and disabled: Configuration of maintenance periods - Google Chrome 2024-02-19 13-20-12-1.mov

Note: This issue can be reproduced in most of list pages and also in some forms (mostly widget forms).