What Adobe program are you using? You posted in the Camera Raw forum, and Camera Raw can not open video files. So I'm wondering what program you are using, so I can move your question to that forum.
Il s'agit bien d'Adobe premier element 14.
I apologize for not being able to reply in your language!
The AX-53 is capable of shooting 4K and saving in MP4 files. They are much bigger and with more data than the 1920x1080 .m2ts files. Consequently it takes a stronger computer for editing with any software. Are you shooting 4K or 1080?
There are a couple things that might help. Do you have the hardware acceleration selected? What are your project settings? How are you making those settings? Is there an indication of needing preview rendering with a colored bar above the timeline? When you output a final video, does it play smoothly?