Alright during the Rey Kylo fight in the water Finn and Jana are inside the wreckage, then 10 seconds later they’re on top of the wreckage, then Rey pushes Finn through the waves, then we see them on Ajan Kloss with zero explanation of how they got there or when they repaired the Falcon. Just a small scene needed to be added to fix this…
The scene with them repairing the Falcon is when Jana reveals that she was a former storm trooper. One can assume they finished up repairs and headed back to base. I didn’t think it was a huge leap.