yes your shots do look underexposure even taking into account that the meter is supposed to be fooled with lots of sky. So yes I agree with you that your XA2 is underexposing. But if it's like the XA there are 2 metering system in the XA. One is only for the meter needle and another for control the actual exposure. Does the XA2 has the meter needle in viewfinder like that of the XA? If it does, does the shutter speed indicated seems right as compared to another camera or just with your experience?
My XA gives good exposures but the meter needle is wrong. If it were to expose like what the meter is saying then it's always overexposing.