Continued to modify the web application to make the checkbox work as it should, the "all tickets" checkbox is set to default but another checkbox can still be checked though it is checked. While checking the tickets module, found out that the dropdown is duplicating a value if the page is not refreshed and when clicking the add or edit button multiple times, modified the function for this for emptying the dropdown first before adding a value and to fix the error in the dropdown. I checked other dropdowns in another module, as per checking the same problem is encountered, modified it as well for the fix, and tested the changes, and as per testing, it is now OK.