When I drag the video file down from the files window, it brings in the video sequence and the audio with it, however, while all the audio loads in, the whole video wont, only about 80% ish of it would show in sequencer and there is more to load in because I watch the unedited footage and its right there. But it wont load into sequencer, I have tried hard cutting and deleting parts of the video sequence in case the amount was an issue, one small addition is the video is longer than the max amount of frames available for blender in the first place but this has never been an issue before as I have edited similar length videos as well.
I faced the same issue just now. You should use ffmpeg to re-encode the video, specifying a bitrate and forcing frames to be duplicated. This worked for me:
ffmpeg -i input.mp4 -c:v libx264 -preset ultrafast -crf 0 -c:a copy -r 30 -vsync cfr output.mp4
This will generate a huge file because it's not compressing the video at all; if space is an issue, you can play with the
-cfr parameter, bringing it to 20 or so (higher numbers mean more compression).