Yes, it's normal behavior, as RB said. Apple "normal" mode text has at least the seventh bit set (i.e. #$80-FF); flash mode has only the sixth bit set (#$40-7F), inverse has neither bit set (i.e. #$00-3F), and you might notice that there's no lowercase in flash or inverse because of the restricted range.
No, you can't switch to 7-bit, because when it was 8-bit originally, you'll get the marker to say that a conversion happened, as you can see.
You'll have to send in 8-bit form, and then perform the conversion after the data arrive.