Custom reports broken after changing rearchiving settings


We are using custom reports but need to see historical data for 15 months rather than the default 6 months. So according to these directions ( we added the following row to the config.ini.php file:

rearchive_reports_in_past_last_n_months = 15

Something has gone wrong since all or at least most of our existing custom reports have stopped working, couple of them don’t show data at all now, some show about 1 month back and some show several months back. Looks like they show data only for time after they have been created/edited, and not before that time anymore. They were working fine before the change. How can we fix them? Can we just remove the row we added and things will go back to normal and all reports will show 6 months at least?

Maybe something goes really wrong with that. I had a problem with weird increasing of the database size. Maybe a look here helps: Database old archive data strong increased