We are using the DXP Commerce beta based on 7.1 (latest available).
The Cancel button does not actuate any action in any browser we test (Safari, FF, Chrome).
Navigate as admin to Control Panel -> Commerce -> <any action, e.g., Catalog> -> <select a catalog item> -> <hit "Cancel">
Notice there is not action. Expected behavior is to cancel action and return to previous screen. This behavior is the same for any edit screen relating to Commerce in the Control Panel.
We are using the standard installation and default theme with no special customizations.