Button hotkeys only showing up after pressing alt, but always work

Hi all, I am trying to set some hotkeys for buttons. I put an & before the letter in the caption of the button which I want to activate. The hotkey works when I press the button, but it doesnt show the underline until I press alt or use a shortcut. How can I get it to always show?

For Windows, this may help:

https://www.tenforums.com/tutorials/97413-turn-off-underline-access-key-shortcuts-menus-windows-10-a.html