Quick boring ruling question

[NLSoldier]

5-5 no limit.

I am utg. I look at 66 and grab 4 chips. Not delaying at all other than the few seconds it took to grab my chips. I look up to see two guys behind me have mucked and one has limped.

Im like wtf hold on and i throw my 20 out there.

Dealer says no you cant raise 3 people already acted. Im like fine w/e ill limp.

Shes like no you cant do that either your hand is dead.

Im like wtf?

She calls the floor over to explain it and they also tell me my hand is dead.

Is this a standard rule?

I understand the thinking regarding angle shooting but they guys behind me acted literally within like 5 seconds of being dealt cards and the dealer did nothing to try to stop or slow them down.