I checked again and when I unplugged midi cables and set internal midi clock this problem disappear.
So what I should to do now because I have motu midi interface, focusrite audio. Project in ableton is only audio track from octatrack.
Ok, but is not typical mute is something like: on restart bar is not synced like is not perfect in tempo and sometimes recorded track are mising. I don t have any other cc only clock from ableton on empty project.
I solved the problem. I made rec trig +1/384 but it was wrong.
Rec trig should be without micro timing, the trig of flex audio track should have +1/384.
Btw you can use - 1/384 microtiming for rec trigs. Hence 0 microtiming for regular trigs.
For regular trigs, I also use swing trigs, all selected, swing = 51. Useful if you use many rec trigs you want to change. I often use a rec trig each 2 steps.
I believe that when you have a rec trig on beat 1 with microtiming at -1/384 the recording will be triggered at the end of the pattern cycle. Source of WTF moments