Palm rejection not working properly in Illustrator on iPad (hand input is drawing lines)

I work on an iPad 8th generation with a Logitech Crayon. Palm rejection works fine in other apps like Notes and Sketchbook, so this is not a hardware issue.

In Illustrator for iPad, palm rejection fails. When I rest my hand on the screen while drawing, it is recognized as input and creates unwanted lines. This makes normal drawing very difficult.

The color picker also often breaks and returns pure black instead of the selected color. Restarting Illustrator fixes it only temporarily; the issue comes back shortly after.

Has anyone else experienced these issues (palm rejection not working / color picker turning black)? How did you solve it?