Hi there, it looks like your blue channel is completely stuffed, I don't there's much you can do to repair it.
I've done a bit of digging on your specific camera, and came up with this website
It has a bit of information about AVCHD Lite and Motion JPEG formats. One thing that caught my eye was the comment "the LX5’s AVCHD Lite mode (even in its best quality SH setting) consumes almost half as much memory as Motion JPEG".
One thing I do know is this - compression kills astrophotography. You want to be recording in the highest quality that you can, with as little compression as you can. I believe you should try capturing in "Motion jpeg" format and see if that improves your images. Try the top two resolution settings and record for about 2 minutes in each, then stack the frames and sharpen in Registax.
For comparison, my Canon DSLR records movies in virtually uncompressed jpg format, and I take this data and turn it into what you can see on my Gallery page here. These images are taken with a resolution of 1024 x 688 with software 5x zoom enabled. Jupiter is only 200 pixels in diameter on my screen - strange as it sounds, that's all you need!
Edited by Tulloch, 17 August 2019 - 06:32 PM.