Could be any one of a number of reasons, but let's try the easiest first. Rainfall from 2 September is 14-odd days old, so currently it will not appear in the day or week plots; it will only appear on the month and year plots. The month plots are only generated/updated every three hours and the year plots every 24 hours. Given you appear to have been moving databases around it is possible the month and year plots have not yet had a chance to update with data from your 'new' database. Try deleting all of the plot files on your WeeWX machine, by default these are the
*.png files in the
/home/weewx/public_html or
/var/www/html/weewx directories (depending on how you installed WeeWX). WeeWX will automatically generate all plot file son the next report cycle, wait for the month and year plots to re-generate and see if your 2 September rainfall appears on the month and year plots. If not post back here and we can look at something else.
Gary