Moving Smooth Node with Option-Arrow Keys Doesn't Always Work

I’ve found that moving a smooth node with angled handles while holding the option key and pressing the arrow keys to be unreliable. Sometimes it will move both dirrections, sometimes it will move only one dirrection and sometimes it won’t move at all. This only applies to moiving the node in single units. Adding the Shift key will always move the node.
To reproduce, draw a circle, rotate it something like 30° or 45°, try option-arrow key moving the nodes.
It seems more likely to happen with 45° angled handles.
Version 2.6.1 (1216)
MacOS 10.11.6

I can imaging what happens. It is always rounded down… I’ll have a look

And sometimes you need to try both arrow keys that go kind of in the right direction. Either one should always work. If you find a situation where the node will not move at all, can you send it to me?