Exception using Parameter in Power Query: A cyclic reference was encountered during evaluation.

Hi Barry_Smart ,

Thank you for sharing and feedback, other users who encounter similar problems also could check the steps in the 'Applied Steps' area in Query editor to find which step is the problem. You may click from the upper step to the lower step in turn, and see which step appears the corresponding error message.

As for the suggestion you made. You may vote the idea here  and comment there to improve this feature. It is a place for customers provide feedback about Microsoft Office products . What’s more, if a feedback is high voted there by other customers, it will be promising that Microsoft Product Team will take it into consideration when designing the next version in the future.

Best Regards,
Community Support Team _ Caitlyn