I did receive 17 upvotes for my answer to this post. I however havent received the 'Nice answer' badge for this question. It's already a couple days old, so data should've been processed by SO already. Any idea why I didn't get the badge?
You got a Nice Answer badge for this post which, as of me posting this, only has a score of 9. I don't see any downvotes for that answer though, so I suspect someone upvoted it, got you the badge, then revoked their upvote while they still could.
The number of Nice Answer badges tallies with the number of 10+-scoring answers you have in total, but since they don't take away badges for answers that no longer satisfy the condition, they make up for that by not awarding for the next answer that's supposed to get you it. So six badges correspond to six 10+-scoring answers. The same applies for answers to questions which have since been deleted, or answers which themselves have since been deleted.