JSON webservice returns asin: null for releases with ASINs

https://beta.musicbrainz.org/ws/2/release-group/ad0bc962-d1da-4ba7-879f-2e68cb096399?inc=artist-credits%2Breleases does not include any information about ASINs (see MBS-5847).

https://beta.musicbrainz.org/ws/2/release-group/ad0bc962-d1da-4ba7-879f-2e68cb096399?fmt=json&inc=artist-credits%2Breleases however claims the ASINs are null, which is incorrect, all except one of those releases does have an ASIN.