I have discovered this as well and the following...
If you press the same button as the pitch selection to deliver the pitch, the meter works... otherwise, it just goes all the way and you can't stop it. For example... if button B is mapped to a 4-seam fastball. If I select it with B and use B to deliver the pitch, the meter works fine. However, if I select pitch B and use A to throw the pitch, the meter doesn't work. It is a workaround, but I agree with you it should still be addressed as this isn't an issue on MLB The Show 21.