The manual for P2020 (yes, it's error-ridden) says that a selection can be filled with a gradient, by dragging within the selection. Not true. The whole canvas is filled.
Hi Petrarch 101,
Hmm, maybe you can tell us which steps you are doing and maybe we can help you get the result you need?
Gradients can definitelly be placed within selections, it's MEGA powerful, see attached images..
Make a selection on a blank canvas with oval tool (I'm still learning what Painter 2020 can do). Choose gradient in toolbar. Drag within selection. Gradient populates whole canvas.
Well well, I restarted Painter2020 and now it works as it is supposed to.
Ooo, glad it's working again!