Menu Bug – major – custom category name – subcats not linked correctly

Directory 8.7 beta

the sample data categories and subcats link correctly:

https://www.mysite.com/category/example-category-9/
https://www.mysite.com/category/sub-cat-2-example-category-9/

however, when i changed the name of the first example category from Example Category 1 to My Custom Category Name and then saved, the respective subcats now do not link correctly:

https://www.mysite.com/category/my-custom-category-name-1/
https://www.mysite.com/category/sub-cat-2/

see how the my-custom-category-name-1 piece is missing from the subcat link?

any ideas? i’m totally stumped on this

thanks