I'm trying to use Flex Markers in Logic Pro X. They finally appeared on one audio track after a half an hour of experimentation and reading documentation (by accident, I discovered that I had to delete all the alternate takes), but another half hour of experimentation hasn't made them appear on a second track. Deleting all the alternate takes wasn't enough this time. The first one has options for Quantize, Q-Swing etc. in the Region pane, but the second one does not. All it has is "Flex and Follow", which is "on" like the other. Both have "Flex Time" set to "Polyphonic" in the edit pane at the bottom of the screen.
Is there any repeatable way to predictably force Flex Markers to appear in Logic Pro X?