I looked through the manual and there are 2 separate sets of instructions on pages 106 and 109 for feeding an HDV signal to this camera, neither of which directly address your issue.
For example, p. 106 says feed an HDV siganl to the input jack, set the camcorder to HDV in and press the Rec button.
P. 109 says Set [PLAYBACK STD] TO [HDV] and [HDV DOWN-CONV] to OFF.
Could they be any more obtuse??
Sorry for not being of more help but, unless someone else has an idea, it sounds like you’re on your own 🙁