Subscription term auto updating when start date changed

Hi ,

When I try to update the start date of a subscription, the term gets changed automatically and I have to update the term again to calculate the correct end date. Is there any way to avoid the term changing from what it was originally, and end date gets calculated based on just the start date update?

Note - the subscription is getting created through Fusion Order Management in Draft status and dates are changed directly in SMC before activating the subscription

Thanks,

Nishi