Toblerone5: On other News, the Patrons are up to 469 ?
Patreon most likely updates the number of people joining in real time (ie, on a daily basis) but updates the number of people who leave at the end of the specific support term. If your page is set up to accept monthly subs, then the number of people who leave probably isn't updated until the end of the month, which is when their subscription would expire.
So it's not unusual for the numbers to rise a few times over the course of a month, then get updated at the end to reflect the people who ended their support. If you follow the numbers every day or week, you might be frustrated to find them climbing until month's end. I think the better way to look at it is the long term pattern, which in his case shows a significant drop since the beginning of the year.