Adding line to change order does not go for approval

Summary:

i have a scenario whereby the requester can create a change order which should go to a different cost centre manager for approval

when i add the line it doesnt route to the appropriate cost centre manager (if i change the original line it does)

we have a block of rules Terms Consensus, which looks for a cost centre change (attribute 1 defined in the application), so unsure why it will find the appropriate manager when changing line 1, but not when adding line 2

i have run diagnostics, and it is reviewing the appropriate rule for the CC change, but not routing in the application to the defined manager for approval