Neither the clone brush nor the healing brush will work. When I select the tool, a circle the size of the selected brush width appears momentarily in the center of the screen. When I press and hold to define the source, nothing happens - no circle appears, only the Assistant message telling me that for the clone brush you must press and hold. I am either on the background layer, or have Current Layer and Below selected for the source.
iPad 12.9 2015
iOS 11 Public Beta
Affinity Photo Beta 1.6.4.48
