You need to enter FULL SKU in order for the main search field to work... not a part of it like it was in desktop Linnworks. Could you please change it to how it works in the desktop version?

Hi,
this feature has now be completed and release
More details of how to use search Open Orders in Linnworks.net can be found in the following section of our documentation.
http://www.linnworks.com/support/order-book/open-order/#SEARCHOPENORDERS

Mark Aldous
Head of Implementation
Linn Systems Ltd