Hey Amos. That is interesting. I remember getting the 'official' name from here:
https://ratings.food.gov.uk/business/775419/star-inn-normans-bay
and I have also seen 'Sluice Road' on a few planning applications.  But you're right - locally it is more known as Sluice Lane and we should probably lean towards what can be found by survey. I'd be happy either way.