Empty bucket not really empty?

Hi!

We are using this particular bucket as a temporary storage - one service stores big (1-500GB) dump files there and another scheduled daily job checks if this bucket contains any files and retrieves them (files are removed from the bucket afterwards). It's a really low frequency traffic and there shouldn't be more than a couple of these files per day - there are days with no traffic at all. Versioning is off, of course.

And this is the problem: this bucket is empty (for days now), but if I look at bucket metrics, CloudWatch claims there is around 1TB of data there in more than 65K of files. I understand that sometimes operations are just scheduled and do not happen immediately, but a week seems like enough time to delete a couple of files.

What have I tried so far?

1. I read somewhere that these files could be remnants from failed uploads, which are not shown because they are not complete files. And that they could be cleared out if I turned the versioning on with a lifecycle rule that deletes everything. Tried, it didn't change anything.
2. I deleted this bucket completely - it shouldn't work if bucket is not empty in the first place (as far as I understand). I created a new bucket with the same name after a day and lo and behold - total bucket size is 1018GB, according to metrics.

If there are files still in this bucket, how do I see/remove them from this limbo? If that's not the case, how do I stop CloudWatch from giving me false information? Why pay for "nothing"?

Cheers