Loop dont work in SynfigStudio-1.3.13

Loops that previously worked well are not working for me.
Only the animation runs and does not repeat anything.

Well, it works for me. Partially.

In this example file, I got a loop error at frame #75… only…
loop-error-at-frame-75.sifz (1.3 KB)

the error is with the x-sheets