I have been entering a lot of tuplets and decided to make a shortcut instead of having to use the mouse and click at the tuplet button on the left hand side all the time. Now, after selecting the bar and choosing the note value (8th note) I press my shortcut. The tuplet button is enabled but nothing shows in the bar selected. Strange thing is that when I do exactly the same thing except for clicking on the tuplet button with my mouse, an empty tuplet is inserted into the bar, ready for input. Why doesn’t the shortcut do the same thing? This surely must be some kind of bug.
The shortcut is for the tuplet popover (which is typically invoked using “;” in note input mode). The button on the left panel creates a 3:2 tuplet, which is a slightly different function. This isn’t a bug, and has been discussed at length in the past. You might try reading this thread for a workaround: https://www.steinberg.net/forums/viewtopic.php?t=127237