FCPX 10.4 Canon C300 long clips not joining together

Hi all,

Since updating to FCP X 10.4, I've noticed that when I import footage shot on a Canon C300 (mk1), long interview clips now appear as several separate clips, each of about 5 minutes and 15 seconds.

I've checked with a couple of other cameras, and long clips recorded on those are still shown as long clips.

Presumably, Final Cut 10.4 update has introduced a problem with recognising takes that span more than one clip length from the Canon C300's MPEG-2 codec.

Has anyone else has this problem? And is there anything I can do to recombine them, other transcoding in another application before I import?

Thanks for your help

Henry