On the charisma saving throw, your class gives you your saving throws that you are proficient in, which tend to be your primary and secondary stats. Warriors are proficient in STR saving throws, etc...you are probably seeing a proficient charisma saving throw that is +2 mod +2 from prof but they just bundled it up as one. Should be clearer.
Great post, there is a lot of inconsistency and mismatches that you found!
