It may be because they are running out of reserve Soviet equipment and are forced to rely on meat assaults to keep up the pressure.
I've noticed the number of artillery system destroyed per day is about half (~25-35/day) of what it was for most of the past year (~70/day).
Same with APCs, the number seems to have halved and the "vehicles and fuel tanks" number has risen to compensate. To me, that indicates the Russians are riding into battle on unarmed vehicles (motorcycles, golf carts, regular cars/trucks, etc.) and are more suseptible to becoming a casualty than earlier in the war.
If that were the case, the Russians pressure/assaults may not have increased as significantly as the casualty number increase would indicate.