Why do UTM parameters vanish after product page finishes loading?

Technical Q&A
1

the UTM link from meta ads disappear when the product page finishes loading and only the variant=xxxxxxxx stays

when someone clicks on:

https://www.artchivesindia.com/collections/kaftan/products/frolicking-monkeys-red?variant=43293190422703&utm_source=meta&utm_medium=frolicking-monkeys-red&utm_campaign=kaftaans

the utm parameters get removed and:

https://www.artchivesindia.com/collections/kaftan/products/frolicking-monkeys-red?variant=43293190422703

only this stays