Problems splitting piles and planting seeds on XboxX

I'm pretty sure this is probably just a user error. I can't seem to get the split option to work in my inventory
I can't seem to get seeds planted after I till the soil.

I must be missing something but I have tried all kinds of things after I push the split button and I don't get anything as the stack is deselected. Same for trying to plant seeds after I till the soil.