In the (Android) app for Patreon, in the Notifications it keeps showing me the net number of new patrons for December 2018 (in the summary for the month). It looks like this is maybe a combination of last month’s and this month’s patrons who have joined and left. There is nothing for January 2019. I have noticed this before in previous months (there is never a heading for the current month, just a heading for the prior month, or sometimes for a month that was 2 months ago) but am finally mentioning it.
Follow-up: On the web version it correctly shows the summary for the current month (January 2019) but if I scroll down to find the previous month, instead of saying December 2018, it again says January 2019, and it shows mostly activity for December, along with one new patron for early January. So these monthly summaries seem to be kind of messed up . . .