I have long had the problem that when MC has been started by the launcher, it requires double-clicks to activate the buttons on the first screen, and in-game if I continue. In version 1.14, I could solve the problem by quitting the program and starting again. Sometimes I had to do it more than once.

With 1.15, it does not seem to help restarting, but I have succeeded if I start version 1.14, quit and then start 1.15.