Shape detection with Apple pencil

Does it work reliably for anyone?

Supposedly in iPadOS if you draw a square or circle etc it'll recognise it
and convert it to the "proper" shape. It never works for me, however. I
just spent some time with online tutorials and regardless of what I do
there's no joy. I can highlight a shape and convert it manual.

Very occasionally when I'm taking notes a word or note get converted to an
arrow or something unwanted.

Also, I get the odd widget appear but have no idea what for. Is there an
Apple page with all the features available for the apple pencil and
handwritten notes?

This is with a 9th gen ipad and original pencil.