Possible bug: New user profiles are displaying full email in username

Hi there! I noticed today that there was a sudden spike in users in our customer community who were displaying their full email as their username. This was alarming because I’ve rarely seen this.

All of these users had created their profile on or after August 6th. Is anyone else noticing this? Is this a possible bug?

We consider our customers’ full emails as sensitive information that we don’t want displayed publicly. Thanks in advance for any help!