Sorry if this has been asked before. I couldn't find it while searching.
For the Fighter, they are stated to be "Expert in all armor and unarmored defense", but Armor Expertise reads:
"You have spent so much time wearing armor that you know how to make the most of its protection. Your proficiency rank for light, medium, and heavy armor, as well as for unarmored defense, increase to expert. You gain the armor specialization effects of medium and heavy armor."
Is it supposed to read that your proficiency increases to Master or are Fighters only supposed to start out as Trained?
Go to Fighter class section, page 141, and check the sidebar that lists all the proficiencies. It is a list of all your initial proficiencies, including all armor, which starts Trained.
Ah! Thanks! Sorry, I must have misread, then.