Can you look at your archived settings in the accounts.json for the affected domain?  It may pinpointed the day on which this happened, and we can correlate that to a possible code change?  Alternatively, you can create a support ticket and our support team could assist.

Speaking with the other devs, we are fairly certain that is a related to a version of the beta last week that lost settings. It was fixed the next day after it was originally reported.

Will have to go through our backups as the archives are only the last few days to be sure when it happened.