Problem with add new values on the fly

I have a problem with an field in the Add page which is set as a lookup to another table with the option to add values on the fly. When I add values on the fly the selected option does not appear in the $values array.

The table is called 'hardware', and it has the fields 'CustomerID' & 'LocationID' which are lookups to separate tables. If do an Add on this table and select an existing Customer & location (list page with search) its fine. If I need to add a record on the fly and use the 'Inline Add', create the record, select the record and then fill the rest of the form and save the values for these fields are missing.

Here is the values array for one where I selected an existing customer and added a Location on the fly:

VALUES ARRAY: Array
(
    [CustomerID] => 2383
    [LocationID] => 
    [Vendor] => HP
    [Model] => A1200
    [DeviceName] => TestHardware
    [CreateDate] => 2018-02-08 10:33:13
)

I have found if I add on the fly, select in the list, and then click on select to go back to the list and select again, then its fine. So it seems it an issue selecting newly added items in the list which is different somehow.

Thanks.