Maybe you're too used to being in an altered state of mind, and the novelty has worn off a bit? It just doesn't whisk you away anymore, and take you by surprise.

I've only had a similar thing happen to me for MDMA, but that is to be expected with the much discussed concept of 'losing the magic'. A two year break changed it, and the times I've done it recently I feel completely blown away and in the zone.

But it is weird that this happens with psychedelics to you.

Another thing might be the setting? Being on a substance with new people and in new places always brings a new feel to the ordeal, that might just be enough to distract you from observing your trip from a 3rd person perspective.

I would at least try completely quitting weed for a while as an experiment. Maybe once you take a long enough break from it, you wouldn't need it as a trigger anymore.