*It may not occur 100% of the time, but it has happened to me all day. I tested it in both 1.14.4 and 19w44a. It has occurred sporadically in previous snapshot versions.

What I expected to happen was...:

When I open Minecraft, I expect to be able to click the any button on the title screen or menu once to get them to do their specified functions. It affects all buttons in the game, such as the title screen, options, and world select, as well as placing blocks in-game (when you enter a world).

What actually happened was...:
I have to press my trackpad twice in order to interact with any menu items or place blocks.

Steps to Reproduce:
1. Boot up Minecraft on macOS.
2. Try to click on a title screen button. Sometimes it may not work on the first click.