How to report a bug in the LibreOffice Calc, the UI element is not showing the text as should be
The ellipsis indicates that clicking on the entry will open a dialogue box. The settings in the menu will be available in the dialogue box.
Maybe the dialogue opened off screen? This can happen if it was last opened on a larger screen.
If you are on Windows, with the dialogue selected (from using the menu) you could press Alt+Spacebar then M for move and use the arrow keys to move the dialogue box back into the visible screen.
If it is something else that I missed in your screenshot then this page should help with reporting a bug, How to Report Bugs in LibreOffice - The Document Foundation Wiki