Can't delete hosted oriented imagery layer after swap view layer source

[BrandonGuo]

I added a few new drone captures in ArcGIS Pro and published the oriented imagery layer as a new hosted service. 

Then updated the oriented imagery view layer source to the newly published hosted service.

Now, both new and old hosted oriented imagery layer somehow linked with the view layer. Both shown have views linked to it. And I can't delete the original oriented imagery layer to save some space. 

Both showing have views.