EOS 550D HDR frame changing does not fit 1:1 alternation

[webmaster1]

As the title, i setted my EOS 550D for an HDR video with:

720P @ 60 FPS
HDR A: 140 B: 800

The result is a video that don't have this (expected) patten: ABABABABABABAB
But it's this: AABBAABBAABB

What's wrong?

[webmaster1]

(UPDATE) Sorry just my error, i forgot to set correct FPS on After Effects