@Shivani - Thanks for creating this video - doing this helps us better understand what is going on!

Your issue is immediately reminding me of this post from last week: Frame won’t delete.

I am not seeing anything in your video that makes me think these objects are grouped or why you can multi-select with Shift + drag.

A few things to try:

• if a browser,
  • clear the cache
  • open the board in an Incognito window
  • disable all browser extensions
• If the Miro desktop app, try resetting the application data (instructions here).
• Create a duplicate of the board to see if you can remove the objects in the duplicate - note: if you continue to use the new board, you may have to set up share access/resend the new board link.

I have also seen these kinds of things soft themselves our by the next day (likely due to a cache being  cleared).