I don't think I've ever had something so confounding happen in a DAW. If I use "Edit > Select All" and then "Process > Slide...", and then select that I'd like everything to move 1 measure forward, somehow everything moves a different amount and ruins my project. This seems pretty simple - like, if something is starting on Measure 5 Beat 1, it should then be on Measure 6 Beat 1. Nope, it's on Measure 7 Beat 1. And the track next to it moved the correct 1 measure.
What am I missing here? And more importantly, why is this even happening? This is such a basic concept it blows my mind that it doesn't just work as described.