Thanks Razvan. I appreciate the comments.
However, I’m sure this is clutch slipping. With false neutrals one tends to see no gear on the indicator and no power at all. You actually need to click the gear lever again to find a gear. In my case, the bike is changing gear, the new gear is displayed and there is a bit of acceleration before it suddenly revs up and stops pulling. I don’t need to change gear to fix it, I just need to throttle back and it picks up again.
I checked the free play at the clutch lever and it was about 5mm – more than the manual says. However, I loosened it even more – to about 1cm free play – and rode again for another 20 miles. This time, no slipping even when I tried to encourage it.
I’m hoping that it’s just poor factory or PDI adjustment somewhere and it’ll stay OK until the first service when it can be properly checked. It’s a bit weird having such a loose clutch lever but at least I can keep on with the break-in.