Even though your new mold had been prototyped (with no issues) and released, there are still traits to learn about your mold. If your products are in the small to medium quantity range, then equally your mold introduction will mirror your product introduction. After an initial push to provide start-up stock, your mold will see a ramp-up of production as product acceptance increases. As the mold sees additional run time, production will get more experience with the mold and some idiosyncrasies may develop. Tendencies to collect foreign material, vents plugging, heat build-up once run volumes increase, are all information that the molder needs to be capturing and include in the mold history.
If you are using a two vendor scenario, separate mold shop and molding shop, a busy molding shop can get into band-aid mode. They do what they can to work around the defect or issue, to keep production going and avoid sending the mold out for revision. Even if the molder handles it internally or finally sends it out, adequate documentation or communication of the observations may prevent an effective or efficient repair.
Always look for the molder to drive problems and issues to the root cause, which includes dealing with the mold. It will make for predictable pricing, on-time delivery, and better relations with your supply base.