The seed data looks like

topic1: createTopic(data: { name: "Productivity", slug: "productivity" }) {
    id
  }
  topic2: createTopic(data: { name: "Tech", slug: "tech" }) {
    id
  }
  topic3: createTopic(data: { name: "Games", slug: "games" }) {
    id
  }
  topic4: createTopic(data: { name: "Books", slug: "books" }) {
    id
  }
  topic5: createTopic(data: { name: "Design Tools", slug: "design-tools" }) {
    id
  }
  product1: createProduct(
    data: {
      name: "Caramella"
      slug: "caramella"
      imageUrl: "<https://ph-files.imgix.net/2363eea3-5840-4ff2-b419-01ecd59321bc?auto=format&auto=compress&codec=mozjpeg&cs=strip&w=80&h=80&fit=crop&dpr=2>"
      description: "A clean, modern blogging platform without the fuss"
      votesCount: 473
      commentsCount: 28
      topics: { connect: [{ slug: "productivity" }, { slug: "tech" }] }
    }
  ) {
    id
  }
  product2: createProduct(
    data: {
      name: "Cover Letter Generator"
      slug: "cover-letter-generator"
      imageUrl: "<https://ph-files.imgix.net/89662bd4-1011-44f7-871b-6f543e9d75f0?auto=format&auto=compress&codec=mozjpeg&cs=strip&w=80&h=80&fit=crop&dpr=2>"
      description: "Quickly generate cover letters with minimum details"
      votesCount: 313
      commentsCount: 6
      topics: { connect: { slug: "productivity" } }
    }
  ) {
    id
  }

Your seed is wrong, same like your model you can't connect after creating some nodes, because you don't have any unique constrains