ATGM Rocket Motor Effect Broke?

Was it an intentional or accidental change to unrealistically make atgm motors appear on the entire flight time? Its only a visual thing; the missiles still have correct motor burn but visually it never turns off. For example the tow2 should only burn for like a second or less, but now keeps the exhaust plume the entire 3.75km flight which looks silly. It makes aiming them harder with all the smoke and flame in the way