You need a lesson on how to utilise a multi-meter when troubleshooting.
Set your meter to read ohms, and then do the following:
Turn power off, and twist the leads together of the wire in tube 2. Next, take each cable in tube 1, and check for -0- ohms. When you find one that shows such a low reading in ohms, then untwist the leads in tube 2 to confirm you have the correct cable. If the reading does not change, then try another cable until you have found the right one.
Now label it so you don't forget!
You now have 3 cables remaining in tube 1 that need to be properly identified.
Next, do the same thing to identify your switch loop. Find the other cable with the -0- ohm reading (if none show this, then throw your switches one at a time to see if the reading changes).
Mark this one as your switch loop.
The 2 remaining cables are your "feed in" and "feed out" and they simply twist together.
Now, take the black
lead from your switch loop, and connect it to the 2 red
leads from your feed cables. Nothing else connects to these wires.
Take the red
lead from your switch loop, and connect it to the red
line that goes to tube 2, and the hot lead of the ballast in tube 1.
Connect the 3 remaining black
leads together, along with the neutral wire from the ballast of tube 1, and both lights should now be wired properly. Restore power for a final check of your work (Of course at this point, you should have connected the ballast of tube 2 back to its incoming cable).
Let us know how you fare.