MarketPress: When last item sold product disappears / gets deleted

MarketPress 3.1.2 , Wordpress 4.7.1
We have about 100 products, most of them are one-of-a-kind products with an inventory of 1.
In Store-Settings - General I chose Yes for Hide Out of Stock Products, and the explanation says "the product will be set to draft when it is sold".

But what happens is: When the last item is sold, the product gets deleted completely, there is no draft, nothing in the trash - nada. The product has disappeard from the Store - Products list in the admin area. There is no chance to edit it as soon as new stock comes in.
I made tests with two products ZZ-999 and ZZ-1000.
ZZ-999 I sold the last item with the option Yes for Hide Out of Stock Products.
ZZ-1000 I sold the last item with the option No for Hide Out of Stock Products.
That is how it looks in the database afterwards:

I assume that the list of products in the Store admin area does not take into account the value "out_of_stock" as post_status.
ZZ-1000 is displayed correctly as out of stock in the front end - so this information must have been taken from the meta data.
For me right now it is ok to use the No-option for Hide Out of Stock products - but the Yes-option would be really nice to have - setting the product automatically to "draft" when it is out of stock....