Beat Mapping to Audio File - what am I missing this time

Hello-

I have done this successfully a few times and so i'm at a loss at what is going on. I've recorded a lot of MIDI to a single tempo... and now I'm using an audio file as a guide to create my tempo map. My process is to open this audio file in the "Audio File Editor" and go into transient mode and move and add transients on bars and important beats etc, that I can use to map the beats to. Than I select this region in the arrange, and view the Beat Mapping global track and start to map beats to the transients in the selected audio file... all is working fine so far... but somewhere in this process it is totally screwing up my MIDI, and I can't figure out why. the midi isn't locked to smpte or any thing like that, and I even tried to turn "protect" on for all MIDI tracks, and the MIDI still starts getting all out of whack... almost like the regions or file is corrupt. Workflow wise, my tempo editing should NOT be changing the position of the MIDI notes relative to the beats and bars, but it is... anyone run into this ever? FWIW, this is the largest scale project I've done this with, sessions previously have had a lot less MIDI, and I'm thinking its one of those places where Logic is just falling apart with too many events or something... but maybe there is just some small dumb tempo setting i am missing. I'm not using smart tempo because the audio doesn't have drums or easily identifiable transients. Thanks for any insight!

Make sure you select Protect MIDI in the Beat Mapping track before you start beat mapping. I gave it a try here and when Protect MIDI is selected, the MIDI notes stay on the grid (which means the MIDI sequences adapts to the new tempo map created by beat mapping).

Doh! I figured it was some little check box I missed. Thank you! I wonder why it doesn't default to that.

That setting changes the MIDI sequence playback tempo. That's not what every user wants.