Thanks for pointing it out, we are aware of it because it's our fault and can only apologize.
Giac paid for a pro-account and wondered if we could merge his free accounts into his main pro-account.
We don't have a system to do that so used it as an opportunity to see if it was possible and maybe develop an automatic function for other users.
We merged the accounts manually in the database but unfortunately the mysql date column is set to ON UPDATE CURRENT_TIMESTAMP(), so changing the track owner updated all tracks to the current date, essentially treating all the tracks as new uploads but retaining play counts.
We knew this would affect the "new" explore filter but didn't think this would be an issue for the "popular" filter as it only totals up plays from the last 7 days, but with hindsight the filter treated all his previous plays as from the last 7 days.
By the time we realized the issue other users had uploaded tracks so restoring the database from backup would've deleted them.
The "popular" filter will gradually return to normal over the next few days but as a temporary solution we've changed the default explore filter to "liked" tracks which seems less affected by the situation.
We were actually thinking of permanently changing the filter to "liked" as it's less susceptible to "gaming". We can use this as an opportunity to test it out.
Once again we apologize for any inconvenience.