I have in some time suffered by a strange bug.

When I'm in stealth mod and i kill an enemy, his friend will begin to investigate and it will show "Caution".

Normaly he would return to his guard rute within a few minutes and it will change to "hidden", but it seems he once again discover the dead body and he begin to investigate again.

It means the sign

constantly change between hidden and caution.

I've tried to reload the game but to no avail