[clone brush tool]

Thanks! I managed to Clone by resetting all the categories under More to sensible figures, i.e. 0%.

[clone brush tool]

I've also been having trouble with the clone tool today (I was a professional image editor for 15 years - I know how to use it!) Close inspection by clicking on More revealed that I had automatically got a line as a brush and it was set to Jitter. Reloading the app did not help return the Clone Tool to normal.