Just did the mission where Michael and Trevor shoot down the airplane and Trevor kidnaps the mafia boss's wife. It switched me to Franklin after that and Franklin has only two missions available, one is the second Lester assassination mission (I already did the first Hotel assassination) and the other is a Green M (for Michael) at michael's house. Nothing happens at Michaels house, I assume because Michael is currently exiled with Trevor as the game told me. I cannot switch to Michael or Trevor. This is my second play through and I do not remember having this issue last time.