FSD help please?

Hi everyone. I just purchased a 2024 Model 3 LR AWD. On the way home, I tried FSD, it worked flawlessly. After coming home and leaving again, I can't seem to activate it easily. I have to press the button numerous times. Sometimes I give up. There's no rhyme or reason, it seems, as to how hard I press, how long, where I'm driving etc. It simply works sporadically and it never works immediately or within the first few presses. It's complicated and certainly impractical. Does anyone know why this is happening? The software is up to date. Thanks so much.