By default there’s a 500ms latency as this gives all target platforms sufficient breathing space for system pauses and other work not to affect the scheduling.
Multiple presses spawn multiple threads which layer over each other - unless you’re using Live Loops in which case it triggers hot code swapping.
What was the code you were running? Happy to help.
We also have a friendly forum to ask questions and get help: https://in-thread.sonic-pi.net