Someone posted about it yesterday and I thought i'd seen it too but wasn't sure. Now I am.
Just played Minsk in a light tank, sat in a bush, 3 tanks pretty much open fire on me at the same time, no 6th sense warning. I hadnt been spotted yet so it wasn't a previous spot. I went and hid for 30 seconds and came back to the bush. After a few seconds, two of them fire on me again, no warning from 6th.
Next game, Ghost Town.
I'm in my Su130 and alt-tabbed for the first 20 seconds so i'm late to the game. I cba with the map tbh so I start driving to one side across open ground. I'm literally 200m away from 2 enemies that appear over a ridge as i'm driving with no cover, no warning goes off.
I get to cover, drive back the same way and the warning goes off this time and they kill me.
It's totally glitched right now.