Does Descriptive Flex Field Segments overrides other attributes not defined in them.

I defined a Descriptive Flex Field at the Payables Invoice Header Level where I defined a code in the Context Field Values .I defined two segmens in the code and assigned ATTRIBUTE1 , ATTRIBUTE2  of AP_INVOICES_ALL as columns respectively to the two segments. Both the segments are kept as displayed and enabled.

I updated a value in ATTRIBUTE14 of AP_INVOICES_ALL of the invoice through update statement.

Now when I queried the invoice and use the descriptive flex field to save values in ATTRIBUTE1 and ATTRIBUTE2, the values got successfully saved, but the value in ATTRIBUTE14 got updated to null.