How to merge 2 separate clips same film

Ok, the title may not say very well what I mean, i use after effects often, and I've been making a clip for a bit, now for a quick overview, i needed to cut my 1 whole clip into 3 parts, due to part 2 not being able to be tracked by 3d camera, call it what you will, so now, i have 3 clips, I've put clip 1, 2, 3 all next to each other, I'm going to talk about the 2nd and 3rd clip merge as I'm not to worried about merging clip 1 - 2.

my question and problem is that when i get the closest frame i can on the 2nd clip, and then go to the same frame on clip 3, its not actually the same frame meaning i cannot just cut out 1 of them.

to put it clearly:

i need to join clip 2 and 3 so they look like they did when the clip was just one big film and not trimmed. but the 2 closest frames to each other of clip 2 and 3 for some reason don't line up? so its like the frames are in different spots on the 2 clips of the exact same scene