Reproduction steps
- Have a self-hosted instance with username-only mode enabled
- Create an alt account with the same username to the system user (which should be the instance name)
Expected behaviour
The name should be restricted because it technically already exists as the system user has it
Actual behaviour
It allows you to use that username. I imagine this is because with username-only mode enabled, the system user still gets the #0000 discriminator instead of just the instance name
Build information
Stable Web 2026.1026.223737, Windows NT 10.0 (x64), Firefox 158.0, Locale en-US
Platform
Self-hosting