Incoming German artillery no longer works in mission .03 of Soviet Campaign
Start Soviet campaign at conscript (easiest) level, run through to mission .03 (Mtzensk); part-way through the game there will be audio warning of incoming artillery, visual warning in the form of a big light-blue glowing arrow, and red artillery flares. However, no artillery shells land. This happened at least twice.
I'm pretty sure there were incoming artillery shells the first time I played the campaign, several years ago.
Soviet Campaign Mission .03 (Mtzensk)
1 v computer Soviet Campaign