My apologies if you’ve already done this. Check the sequence to see if you have all your video and audio tracks that you are wanting to export are active, check to make sure that the your in/out marks are either not set or are in/out around the area you want to export.
Then check your export settings you are using for uncompressed, look at the “Use marks” and/or “Use selected tracks” (can’t remember the exact wording) options and set them appropriately. “Use Marks” will export only the area within you in/out marks, unchecked it will ignore them and export the entire sequence. The “use selected tracks” option will export only the tracks that are selected in the sequence, unchecked it will export all the tracks, regardless.