Is it just me or sometimes if you don't appeal super quick you then can't appeal? I've had 2 just now where they edge to gully... I jump up in my seat in delight (been a long day in the field) then forget to appeal then press it nothing happens then skips to next ball lol.
Also Had a few caught straight off the pads and its been given out even tho nowhere near bat.
You definitely have to be fast. Although, I've had lots of occasions where the AI nicks it behind for a catch but I can't appeal, no matter how fast I am.