Failed login attempts not reported

We have installed the free edition of this plugin in July 2021 and it worked fine until mid October.
Just after that stopped to send email notification about failed login attempts (which is strange but it could be we are being forgotten). Just when I look at the dashboard it says “Hooray! Zero failed login attempts today” and in the log I see nothing at all for November, December and January. Just I see the graph “Total Failed Login Attempts” and the table “Failed Login Attempts By Country” growing the shown numbers every day (which seems to indicate that there are failed attempts to login).

Is that due to the fact we use the free edition and some sort of trial period expired?