This means another account logged in from the same network as you did. Common triggers include logging in from a corporate/school network or using a VPS. Krydos can probably provide extra clarification if you'd like. I'll cancel the pending suspension for your account in the meantime.
Domain name changed to worksyncpro.helioho.st. Also, if you want to still add worksync.helioho.st, a staff member can set that as an addon domain for you.