In the first case you are looping around each checkbox. In the second case you are doing the same but don't you need to also loop around each cell in your range of interest?
The attached code looks for checkboxes in "testRng" and outputs in "outputArray" for each cell in "testRng" either "No associated checkbox" or the cell address if there is an associated checkbox.
I'm afraid it has drifted quite a long way from your code, so I hope you can still get at least a little something of use from it.
Attached is the associated workbook
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