Some users randomly assigned a username

Hello!

Users register to my site (using Gravity Forms but I don’t think this is an issue with Gravity Forms) and it works fine.

The issue is that SOMETIMES WordPress auto generates a random username (‘chocolate’ in the most recent occurrence), replacing the text that was typed into the username field.

So, after registration and after clicking on the link from WordPress to accept the registration, the email that is then sent with the password includes the random username, and not the username the user gave.

Any ideas what’s going on?

When it does this, it also strips the user’s first and last name (I have these fields in the registration form) from the backend, so I’m left with a random username and their email address only.

??