R30510 not working as desired

Hello

We are trying to use ECO to change effective dates in BOM as follows     

Parent Item A,

Component1 -  B, Component 2 - C

Current dates - effective from and effective thru

B - 01/01/2015 - 25/07/2016

C - 26/07/2016 - 31/12/2040

What we want to change -

B - 01/01/2015 - 04/10/2016

C - 05/10/2016 - 31/12/2040

It always shows existing bill ineffective on requested date -

Thanks