Sticky header for table not working after edit

Summary

In the new Confluence release, as mentioned here, the table headers in Confluence Cloud is supposed to stick to the top when large tables are scrolled.
PS: The sticky header will not work when the user edited the table. If user copies and pastes back the table, the sticky table will work. However, when they edited the table, the sticky table will stop working.

Steps to reproduce:

1. Create blank page
2. Create a large table, with header
3. Save the page
4. Sticky table will not work.
5. Edit the page
6. Copy the table
7. Delete the table and paste the table again
8. Save the page.
9. Sticky header works
   For details behavior please review the attached video.

Observed Behaviour
Try to scroll and header will not be sticky on the top

Expected Behaviour
The table header will stick when we scroll the page.

Video

Recording #15.mp4