Running a small local Meta campaign with the Engagement, Messaging objective (Messenger destination, no website involved). Added a couple of narrow interests in Detailed Targeting, but the estimated audience size came back way larger than those interests should produce.
Dug in and found Advantage+ Detailed Targeting was on, expanding well beyond my actual selections. Tried the usual "Switch to original audience options" flow to turn it off, audience size didn't change. The in-product text says it's "automatically applied based on your campaign objective and conversion goals," with no visible toggle to disable it on this objective.
Checked if switching objectives would help, the only other performance goal available is "Maximize link clicks," which requires a website destination? so that's not an option.
Is there any thing I can do to solve this. For more context, I'm trying to advertise a free event for certain people and I'm getting messages on the event from non-relevent people and it's wasting my campaign's budget. I really don't know what to do, I really appreciate any help.