Assertion reuse in another test step

I right clicked on a TC and cloned assertion

it partially worked why partially because it creates duplicate assertions1

I have attached the screenshots.

See Duplicates!

its still fine though I can delete the duplicates!

I will contact support about this

I use the three options at the bottom of your screenshot to delete existing assertions and to overwrite as necessary. There are two check boxes "Overwrite Existing assertions" and "Remove all existing assertions" are very useful once you understand how they work.