Yes, me too, happened on 4th of June on Buddyspike Syria Modern.
I have ACMI File where it is clearly visible that HARMS are going somewhere, but not on target.
4 weapons just fly right over the target, and are going into ground far behind the target.
I was using HAS mode, locked the SAM, wait for the rectangle to flash, fire (as always).
I never had problems with that in former versions of OB.
I am still investigating, since I can't say for sure if the SAM units kept their radars on during my engagement.
Are you sure about seeing the SAM's radar active until impact?
Edit: Just did a test sortie against SA-11, had no problems. HARM flies to target at higher altitude, then dives steep, boom.
Seems all OK so far...