Seems something went wrong even before booster cut-off and staging. See 02:37 min. into this video of the launch, something can be seen detaching from the rocket and spinning around just before the internal shot where the "gravity indicator" suddenly rises and then the bouncing starts. 2 seconds later the debris cloud can be seen.
That might be the payload fairing coming off, as planned. You want the fairing near to sea level atmospheric pressure, as you need the aerodynamic shape: but once up high enough, the benefit from the fairing is less than the benefit from dropping it, so you do not need to spend fuel to lift it higher.
I'm not familiar enough with the Soyuz launch timeline to know if the fairing is meant to come off before, during, or after booster separation.