Thanks for the responses ...
Below image shows the various layers and the "trail" I see when all selected. I too think this has something to do with feathering of the edge ... but so far nothing I have attempted has worked. Did not delete the sky layer and start over, just tried modifying the selection settings via select->feather, select-refine edges, select->smooth, but these don't seem to "take". For example I select the sky layer, select->feather, set 5px, hit apply, go back into select-feather and the px is back to 0. I am probably trying to modify the selection properties in a way that can't be done after the selection has been created? As I said, I am new to Affinity .
I will take a shot as deleting the sky layer and recreating it with feathering ...
thenderaaa got a reaction from firstdefence in "Trail" left around selection after deselection
thenderaaa got a reaction from John Rostron in "Trail" left around selection after deselection