Fusion: Resize node doesn't work with 'Keep Frame Aspect'

Add clip
Go to Fusion
Add Resize Node
Set to view node
Adjust width - pic scales horizontally
Reset
Check 'Keep frame aspect'
Adjust width - no change in size
(NB works OK if merged with background - I guess it is resizing but resizing the canvas to match?)
Plus, remembered that Transform is better than Resize for simple Repo
Go to Fusion
Add Resize Node
Set to view node
Adjust width - pic scales horizontally
Reset
Check 'Keep frame aspect'
Adjust width - no change in size
(NB works OK if merged with background - I guess it is resizing but resizing the canvas to match?)
Plus, remembered that Transform is better than Resize for simple Repo