Hi Thimo and Inge, sorry to jump on your thread, but I also have the same problem with the products the plugin is displaying…
In Spreadshirt I have uploaded a design and chosen the categories of products I want to use the design on… these include t-shirts, hoodies, caps, bags, phone etc. On my shop all of those products are displayed.
However, on the plugin, only the t-shirt is displayed. All the other products are missing.
As Inge pointed out, i believe spreadshirt may have changed the way it works!?
Thanks!