I have a 2 in 1 tablet it is staying in portable mode

I have a 2 in 1 laptop computer It is very nice no problems but 1 I can't get it out of portable mode went to settings turned auto screen rotate on and off and it was still stuck in portable mode the only way I can't put it in laptop mode is turning it completely off and turning it back on I sign in to it and I will just go back In to portable mode any way I can manually rotate the screen