I cannot alt-tab back to the game when playing online, the only time it does return is when the next session starts...
I think this is "normal". There is a "workaround" for this issue: Open taskmanager. Click on rFactor. Then on Switch to... Every time I had this issue this helped.
Same for me too. It is really annoying because i always have to close rF2 in the Taskmanager and: Doesnt work for me