The you don’t have a TMB12A05, no matter it is marked as such. From the TMB12A05 data sheet:
This is not a true piezoelectric speaker but behaves similarly. Instead of a piezoelectric crystal that vibrates with an electric current, this tiny speaker uses an electromagnet to drive a thin metal sheet. That means you need to use some form of alternating current to get sound. The good news is that this speaker is tuned to respond best with a square wave (e.g. from a microcontroller).
Emphasis mine.
So that’s why I wanted to see the program you used.
But I never argue with success or the empirical process.
I will say that often it is a mix up of buzzer, beeper, squeaker or tweeter operating type that slows ppl’s progress.
a7