Ok my bad guys,
So the previous poster is correct, when on Autolamp, it needs to be dark enough to be able to turn the headlights on and thus unlock the toggle function of the high beams.
Since I have daylight running lights, the front headlamps are always on so that's why I was confused. I guess the Autolamp is really turning the headlights "off" during the day but the DRL overrides it.
So that explains why the high beams did not toggle the other day. I only used my high beams when I was trying to signal to this idle car that I was gonna pass him (so he doesn't open his door) during snowy weather (but it wasn't dark enough that day for the autolamps to turn the headlights on I guess). This also explains why it wouldn't toggle high beams when I tried it before I went to work in the morning.
But today as I was pulling into my driveway in pure darkness at night, with autolamps, the high beams did toggle on.
Mystery solved. Thanks for the help everyone!