I think there might also be a subcultural difference, too, because there are different types of “tryna” that are used by different groups of people, and maybe being used to a more versatile “tryna” would make “tryna not x” more natural to speak.

Tryna A: “I’m just tryna screw in this lightbulb,” “I’m not tryna hurt you”

Tryna B (expanded tryna, not spoken by everyone, mostly skews younger and bro-ier I think): “You tryna go to Taco Bell right now?” “You tryna chill tomorrow?”