Hi,
You can check the forum mentioned below.

https://www.odoo.com/es_ES/forum/ayuda-1/no-auto-delivery-order-17337

Hope it helps.

1)The fact that once you uncheck the checkbox “Trigger delivery orders automatically from sales orders” by following Settings>Configuration>Sales>Warehouse features

2)You will see that a pop menu arises mentioning that some modules (E.g. Warehouses,Point of Sales,Portal Stock etc..) would be uninstalled on disabling this check box.

Refer Screen shot :- http://prntscr.com/adey9u

3)Hence , as Warehouses module gets uninstalled all your Sales which were associated with Warehouse has turned turned red and status as “Undefined” as they have no warehouse associated anymore.

 Hope this helps.

Globally: Go to Settings --> Configuration --> Sales and under "warehouse features" uncheck the box that says "Trigger delivery orders automatically from sales orders".

That should do the trick.

This setting does not count for sale orders that were made in the past, only for new ones. Do the new sale orders appear as red? If so, have you made any custom modifications? If it is neither then you might want to report a bug.