To cross-fade in Logic Pro requires you to first select the region you would like to cross-fade and then use the "Fade Out" slider to adjust the cross-fade amount, after first switching the "Type" pop up button to X for crossfade.
Cross-Fading In Logic Pro X From The Keyboard…
To cross-fade in Logic Pro requires you to first select the region you would like to cross-fade and then use the "Fade Out" slider to adjust the cross-fade amount, after first switching the "Type" pop up button to X for crossfade.