5e Character Sheet - Proficiency Bonus Question

I'm not sure this is the right forum, but I'm gonna start here. I'm using the D&D 5e by Roll20 character sheet.  It appears that when I drop in a new weapon the proficiency bonus box is checked in the attack settings - even if I'm not proficient with that type of weapon.  For example, I'm a rogue and I drop in a warhammer.  I am not proficient with martial weapons, so I shouldn't have the proficiency bonus. Is this working as expected, and I am supposed to uncheck that box (or simply not use weapons I'm not very good with)?  I'm okay with that, but I want to understand. And no, my rogue doesn't want to use a warhammer, it was just a test when this question came up.

Yeah you're supposed to uncheck the box for weaposn you aren't proficient in. It's just convenient that any weapons taken from the compendium have by default it checked as most characters use weapon they are proficient most of the time.

Cool, that's kind of what I thought but it doesn't hurt to be sure I'm not just a crazy person. Thank you, Andreas!