When members log off the site there logged back in as offline.

Hello all,  I have a question I hope someone can help me with.

  Members log off the site in online mode, then when they log back in they are  shown  as "offline" every time, including me.

 Does anyone know how I can change the defalt login to online?

Thanks Guys, have a great one...

If anyone has this problem in the future... I had the desktop app installed and it was causing the problem. Uninstalled it and everything's back to normal.