So, the difference between "At the beginning of your end step" and "At the beginning of each end step" is pretty obvious, but what is the meaning of "At the beginning of the end step" and how does it compare to other two?
All three wordings are present on cards and seem to be used on new cards, here are examples from recent standard sets:
Thassa, Deep-Dwelling: "At the beginning of your end step"
Underworld Breach: "At the beginning of the end step"
Resplendent Angel: "At the beginning of each end step"