Is this a known bug? And can it be fixed?
Also no other AntiVirius software causes this issue.
Yeah, it has been seen before. I noticed it once....I forget, maybe 6 months ago or more? There was a thread on it, a forum search might turn it up for you.
As for fixing it, I forget if there was a way, but I know mine at some point stopped doing that on its own, maybe after a Win. update. Maybe if you track that thread down you might find one, but I just didn't care once I realized it was just cosmetic, that I still was connected despite the yellow sign, I stopped caring about it.
As far as "no other anti-virus software causes this"? ...
c'mon, don't put your foot too far in your mouth there, no offense, but I can't see how you would know that for sure one way or another, with all the brands out there.