For some reason, this shows 6 episodes. There should be only 3, and in fact only the first 3 episodes have original airing dates. The 1st is 1 hr. 57 min., and the other 2 are 1 hr. 30 min. each.
I’ve checked the barcode in CORE, and it indeed only contains three episodes.
I’m not sure what went wrong, but the best solution would be to remove this mini-series from your collection and add it again using a barcode search.