my steam name on top right sometime lights up blue like i am online

[Kind.]

is this a sign one of my games is hijacked?
cause i never come online. i stay private/offline unless i want to message old friends.
i dont go on my phone to browse steam. that's always offline/signed out.
i usually go months at a time without playing videogames.
sometimes i see my account name on top right of this light up blue for a few minutes then goes back to offline status.

is this a bug? or a possible game account breach?

[Kind.]

anyone else ever see this happen?
name on top right of steam client, comes online by itself (blue) then disconnects?
while your account is offline? 0 cellphone steam app online. etc.

is it a steam bug, or is one of my game accounts pwnt?