Add service to existing contract from OM

The current value of profile option "OKS: Category for Order Management Originated Contracts" is Service.

We are trying to add service to an existing contract from Order Management. The exisiting contract is of category Warranty and Extended Warranty.

So whenever the order is fulfilled, the service line is not added to this contract.

It errors in the iNterface with error "Request ID : 21083580; The Contract Category selected in the profile OKS: Category for Order Management Originated Contracts does not match with the merging rule category WARRANTY;"

Please let us know if there is a way out to add service lines to an exisitng Warranty and Extended warranty type of Contract while keeping the value of profile "OKS: Category for Order Management Originated Contracts" as "Service".