What you'll see
Your menu does not appear on Lieferando. In Stream, the Lieferando location panel ("Lieferando approved – Manage your DSP location status") shows the status MENU_FAILURE_UNKNOWN with an error like this:
DSP_REJECTED: Failed to publish menu to lieferando, with error (400) (POST /menus) lieferando API Status Error: {"error_message":"Invalid request body - validation errors: [menus.0.categories.2.items.22.portions: Item with a single portion is not valid menus.0.categories.2.items.24.portions: Item with a single portion is not valid ...]"}
This is Lieferando's own error message. The list can name several items, and the text may be cut off in the dashboard.
What it means
Lieferando rejected the menu when Stream tried to publish it. Lieferando only accepts two kinds of items: a standard single item with no size options at all, or an item with two or more sizes. An item set up with exactly one size falls in between and is rejected.
Lieferando validates the menu as a whole, so one invalid item blocks the full menu, not only that item.
How to fix it
In your POS, find the items that have only one size option.
For each of these items, do one of the following:
Remove the size option, so the item is a regular item with one price.
Add a second size, if the item comes in more than one size.
Make sure every item with a single size is corrected. One remaining invalid item still blocks the full menu.
Re-push your menu from your POS and let Stream Support know. We will check that it came through on our side and confirm it is live on Lieferando.