I created an account because I have an issue to report and email support is temporarily suspended.
I chose a preferred display name. When I clicked Submit, in one fell swoop, this forum website told me that the name was already taken, changed the display name to my last name, and completed account creation with my last name as my display name.
This is unacceptable behavior. My last name is pretty rare and thus effectively identifies me as one of a handful of people, only 2-3 of whom make much use of the internet.
Then, when I went to change my display name in the preferences, it prefilled the dialog with MY FULL EMAIL ADDRESS.
This is absurdly bad behavior for forum software. Please look into it.