Currently seems like the system temporarily hold accounts that “type too fast” after creating a new account as a measure to prevent bots.
Which is fine. However, I don’t understand if there is somewhere an option to change this length. I would prefer is those users are suspended for a longer time so that I can be sure that someone from staff review it. Currently, the time windows seem very short (but it might depend on from the availability of your staff I suppose)
I believe this setting has had a recent update and is now called Fast typing threshold[1]:
Fast typing threshold
Minimum amount of time in milliseconds a user must type for their first post. If the threshold is not met, the post will automatically enter the review queue. Low is 1 second, standard is 3 seconds, high is 5 seconds.