Audio issue with 4K83

Hey.
So I got the full 4K version of the package and I wanted to down convert it to regular Blu. I had allot of problems converting it, TSMuxer couldn’t handle it, Adobe Media Encoder couldn’t handle it (something about the file not having a set frame rate) but DVDFab had no problem crushing it down to manageable size and format.
So now I have the film in .m2ts format that I can Demux but for some reason the video and audio are not the same length. This is probably due to the afore mentioned frame rate issues but weird none the less ( the basic film only blu I burned from the DVDFab ISO plays and syncs fine).

So I wanted to know how can I either change the frame rate on the film to match the audio? A more simple question is; what is the frame rate of the audio?

Why don’t you use the 1080p version of 4K83, which is out there, to burn to a blank Blu Ray disc instead of the using the full-4K version to downconvert to 1080p to burn to a blank Blu Ray disc?