Bug 502295

SUMMARY
When adding a "/" in a submenu name, the entry is either not saved or saves in an erroneous state. The application does not give a warning that the character is disallowed, the help doc does not mention this limitation, and pressing the save button, the application acts exactly as it does with a valid save. 

STEPS TO REPRODUCE
1. Create a new submenu with a "/" in the title, such as "A/V". Add items from other menus. 
2a. Do not save, exit the program, and save via the "Save Menu Changes?" prompt.
3a. View menu entry in menu launcher, note incorrect name.
4a. Re-enter menu editor and attempt to change submenu name, note changes do not save.
2b. Save via the toolbar save button.
3b. Exit application, open menu launcher, note submenu is missing.
4b. Re-enter menu editor, note submenu is missing.

OBSERVED RESULT
New submenu either does not exist or saves with only the portion of name before "/", and saves in a state where the name and icon cannot be altered.

EXPECTED RESULT
Either: menu entry should save properly; or if the "/" character is disallowed, a warning or error message should appear to notify the user. 

SOFTWARE/OS VERSIONS
Operating System: Manjaro Linux 
KDE Plasma Version: 6.3.3
KDE Frameworks Version: 6.12.0
Qt Version: 6.8.2
Kernel Version: 6.12.20-2-MANJARO (64-bit)
Graphics Platform: Wayland
Processors: 4 × Intel® Core™ i3-7100 CPU @ 3.90GHz
Memory: 7.7 GiB of RAM
Graphics Processor: Intel® HD Graphics 630

ADDITIONAL INFORMATION
I'm not sure if my issue will be clear from the above, so here it is in story form: I was attempting to name a new submenu "A/V". When saving via the "Save Menu Changes?" prompt upon closing the window, the submenu instead saves as "A", but the name and icon cannot be edited upon re-entry into menu editor, although applications can still be moved in and out. When saving via the toolbar "save" button and then closing the application, the submenu does not populate at all on the menu launcher and is gone the next time I enter menu editor. I was able to delete the submenu and create a new named "AV", so I have resolved my use case, but the application bug is still present. 

This is my first issue created. If there's anything I should do differently in filing please don't hesitate to let me know.