Tempo changes happen on a tempo 'map' that aligns with the song.

As a tempo change happens it sets the tempo. It doesn't change again until another tempo map change (at least using the metronome).

When it's on a track RB has a chance of looking back to check the last tempo change when it loops.
The metronome just follows whatever it was told last.

So if you changed tempo from 100 to 112 and then loop back to a spot where the tempo was once set at 100 the metronome thinks it's still 112 because nobody told it to change.
Metronome is nice for a beginner starter tempo, but always make a click track instead .. just the best advice I can give here.
Noel's long shot was the likely answer and points out a weakness in Metronome.
/it is dumb and just does what it was last told, no awareness of its surroundings

That is why it works the first time thru; it gets every message in a map as it happens linearly

Last edited by rharv; 1 hour ago.
I do not work here, but the benefits are still awesome
Make your sound your own!