By accounts in telegram, the fighting wasn't that heavy, but advancing under artillery fire in places advantageous for ambushes was.
Russians had scattered firing positions flooded with levies, and draftees, with regulars very far away. Levies stood to death, but did little, and regulars fell back very quickly after taking return fire.
Whomever commands Russian defence there decided to maximize the advantage in trading territory for bodycount.
So, Russians falling back quickly, and easily for the first time is a bad thing.