Welcome to MyPureSupport!
Per your question, I am not entirely sure why this happened, however, it isn't the first time its been seen.
1. Login to the FSM using the userid of PE and the password you currently have. If that one doesn't work, try the previous password if you can remember it.
2. Run this command smcli chuserpwd -v -u USERID -o existing_password -p new_password
Let us know how you make out.