It's actually highly common place for undiagnosed adults on the spectrum to be misdiagnosed with anger management issues. The reason is because during a sensory overload or meltdown, our fight or flight response becomes hyper stimulated. So it can very easily present outwardly as anger. I only found this out recently from my pdoc because I had been diagnosed with anger management issues during my teens and she said that it was more than likely not anger management issues, but a side effect of meltdowns and we just didn't realise what they were at the time.