I have absolutely same issue on same firmware.
EDIT: Touch squid presented me also with a message that said "No IR blaster found."
I have looked on ebay and it seems it is pretty cheap part to replace (couple of $).
It is a flex cable with front camera, ir blaster, proximity and light sensor.
So it's completely broken then?
Are you going to replace it by yourself? Don't think I can do that.
Has anyone tried doing a factory reset and see if that fixes the issue?
Edit: Furthermore, it would be so strange if it was broken because the firmware must have done something then. I have never dropped the phone or anything.