I see OP mentioned EVERY SHOT came out underexposed. Plus OP has +1 exposure comp dialled in. Even if he pointed the centre weighted meter to the subject’s white shirt, it should not be this underexposed.

Good point. But the OP mentioned going out to "take some portraits", followed by "sunny/cloudy day" so it's fair to assume the entire roll was used for the same session, quite possibly with the same model. A series of portraits of a black model wearing a pure white shirt = high contrast on every frame.

This is challenging for most meters. In fact, it's every wedding photographer nightmare: a bride's white dress next to a groom's black suit.

In the example above I would have used incident metering with +1EV compensation.