Devices
The “Devices” list, in “Settings › Account and security”, shows the browsers and devices signed in to your account, with their last activity.
Check where you are signed in
Each line shows the browser, the system and when it was last active. “This device” marks the one you’re using.
Sign out of the other devices
“Sign out of the other devices” closes every session except this one, for example after using a shared computer. PixelBureau asks you to confirm it’s you first.
Something looks wrong?
Sign out of the other devices, change your password if you have one, turn on two-factor authentication, and write to support.