I don't know what you mean exactly by "trigger your autism". But understimulation is a real pain for me. I hate feeling bored, it's almost physically uncomfortable.
Some here suggested ADHD as a link (I am not diagnosed with it, I just have it in my description because I (and others) see some real ADHD traits in me, although I might not qualify for a full diagnosis), which I don't know about because I have no problems with keeping still, as long as my mind is busy reading or watching or working on something. As a kid, I wasn't hyperactive and had no problems to focus, so I don't really qualify for ADHD.
I have the constant need to keep my brain busy. I usually listen to something - music, audio book, podcast - while doing things which don't require much thought. If I can't, it feels like my brain itches or something.
"Not thinking about anything" while being comfortable is only possible for me in certain situations - e.g. while I'm kickboxing (and realistically my brain is not thinking nothing, it's just channeling all focus), while I'm listening to some music (which is still stimulation), or while I'm in nature looking at and listening to running water, waves, birds, etc.
I also hate it when someone talks at lengths about something that doesn't interest me - I feel almost physically uncomfortable then -, when someone just won't get to the point of their sentence.