I'm skeptical of that claim. I won't say that the burning didn't happen, and I'm extremely hesitant to take even a hint of truth or credulity from western media. But it seems like that video is from back in 2015, rather than the current conflict in 2022.
Of course the overall conflict dates back many decades, and the UkraNazi coup and Donbass shelling started years ago and never stopped and this conflict basically continued to this day, but I'm hesitant to say that the story of Ukrainians burning a Russian soldier on a cross happened recently.
But still, it was a horrific event, no matter what year.