Firstly that camera records H264 codec and you need to transcode that to an edit codec like ProRes. Secondly dropping the files into an HDV sequence is a poor choice as it is highly compressed and interlaced.
If FCP is interpreting the files as upper, then it thinks the file is interlaced. I don’t know that camera so I can’t comment on whether FCP is getting it right or not. Some progressive formats are embedded in interlaced codecs, a technique referred to as psf.
So there are possibilities that you have the wrong sequence settings, the wrong codec for smooth render free editing and perhaps the wrong understanding of the configuration of the camera codec. So there are numerous reasons why the playback will look bad. Do not use the canvas as a reliable judge either.