This happened overnight, only on this branch, one of the lower small ones. Any ideas? I've never seen this before. No obvious issues with the branch, just the dead fan leaves
Have you been stabbing around your root zone lately? any physical damage to the plants or pots? have you been moving them etc? if it's just that one branch and not happening on any others I wouldn't stress too much about it
I suspect damage that restricted water and nutrients to the branch. The bigger leaves usually die first because new growth has priority as the plant tissue struggles to survive.