Formerly purchased marketplace items no longer register as "purchased"

I have not played the game for a number of months, but now I cannot view my costumes on the nintendo switch version, and on PC most of the things I have purchased in the marketplace are no longer available to download.

 

Surely this is a mistake; I bought and paid for most of those things on the Switch version, and now I cannot log into that version of the game at all, nor can I even access my purchases on another device. Please fix this!