If they buried a new line it will also settle over time. Usually they don’t put a lot of effort into backfilling the hole after running the new pipe. You can fix it up nice now, and once it get rained on for a while and settles you will see the area they trenched. It goes a long way in advising the customer on what they can expect and settling is a normal thing. Then they know it’s not your fault and can expect to “fix” the settles area again later.