The url when you click on the Receive button from the subscription-detail.pl page is different to the one used in Actions from the serials-search.pl results screen: Subscription-detail.pl: /cgi-bin/koha/serials/serials-edit.pl?subscriptionid=39&serstatus=1,3 Serials-search.pl: /cgi-bin/koha/serials/serials-edit.pl?subscriptionid=39&serstatus=1,3,7 It would be good if the two options for receiving issues behaved in the same way.
I've traced this back to 2009 where these statuses were first added to the code base. It looks like these numbers can affect the status of the subscriptions on the receive page, but it also looks like these numbers could be done without. I'd be keen to get a second opinion on this though!