Is this a bug on facebook?

[Rares]

I have 3 devices: an iphone, ipad and a laptop and I check my FB ACCOUNT everyday, sometimes on my laptop or my iphone, sometimes on my ipad BUT I always make sure to sign out: on iphone and ipad I always close the app and kill it in the multitasking tray and on my laptop with Chrome I click sign out after I'm done but my friends say that I spend my time on facebook a lot, a coligue in my class checks his FB all the time and when he looks at my FB, I am always online even though my laptop is home sitting there password protected and shut down and the FB app as always killed on my iphone. Why am I online when I am actually not? I also changed my password and it's just a bunch of random words and numbers.

[ABC]

nope it's not a bug. you have to make sure that you go offline before you sign out through the laptop. change your chat settings to offline before you sign out. otherwise your friends might see as you are online 24/7.