Okay, it seems like you are right. I don't know why it stopped happening when I turned off SVP earlier, but now when I turn off SVP it still happens rarely.
I have switched from madvr to EVR and I haven't seen the green artifact yet.
Any idea why madvr is causing this to happen? Maybe I didn't install madvr right.
Sorry for the false alarm about SVP, and thank you devs for the help