while generating Sitemap of a next.js application its inluding dynamic segment in the url of sitemap why?

Question

My website is build in next.js and when i was generating sitemap by an online tool https://www.xml-sitemaps.com/ its including dynamic segment ([grade],[subject]) in the url like https://www.shreersctutors.com/worksheets/[grade]/[subject]/worksheets/grade-4/worksheets and then after the dynamic segemnt it adding correct grade but again worksheets i dont know how

i checked my code all the routing logic is straight forward like this

<Link href={`worksheets${item.grade_link}/maths`} key={index} sx={styles.link}>
  <a>
   <Typography color="#fff" fontSize="16px">
    {item.grade_name} Maths Worksheet
   </Typography>
  </a>
</Link>

and 

<Link
  scroll={false}
  key={index}
  href={`/worksheets/${getSlug(grade)}/${getSlug(subject)}/${topicArr[0]}/${getSlug(
  item, )}`}
 >
      <a style={styles.subtopicsItems}>{item}</a>
</Link>

this is how I redirect the user to another page