The day your Actor migrated, all your Rental subscribers started to be billed for events. However, so that they're not double-charged, their rental subscription was pro-rated. So if you have a customer who started their rental on January 10th and they paid $30 a month for your Actor, and then you migrated on January 20th, the customer started paying per-event from January 20th even though their rental subscription was for a month from January 10th. They will receive approx $20 back from the $30 they paid for the monthly rental, as 10 days is approx 1/3 of a month. It will show on your payouts invoice as a chargeback, but it's only deducted from the full rental fee they already paid.