Possible issue with 'Dynamically Changing Group Title From Subfield' (row counts are getting off)

[lifeflowdan]

I think there is an issue with this snippet, and perhaps more specifically with the below part. Under certain conditions, the Row Numbers get off. One replicatable condition is if you have three rows, delete the third row and add another. That new row should be row 4, but it displaying row 5.

I tried subtracting hidden (aka deleted) rows, but it wasn't working. I tried but my css attribute (visibility) and by the class you assign rows when hidden. Neither worked.

I didn't see this as a known issue. I'd be thrilled if you had a possible solution, as this snippet is particularly useful for what I'm doing. Thank you!
rowindex = $this.parents( '[data-iterator]' ).data( 'iterator' );