This is the designed behaviour. Given that you can already move the caret by a duration other than the current grid setting, e.g. when you have the grid set to eighths and enter a dotted eighth, there’s no good reason in our view to force the caret to snap to grid positions if you change the resolution.
Yes, that was my point (although again, it feels a bit like straining at gnats). When I move the cursor left, if expect it to move to the next available grid location. But it doesn’t; it jumps to the previous measure.