For me it was the problem related with Spring Filters and storefronts.Starting point - https://answers.sap.com/questions/12765584/cannot-able-to-access-to-the-site--failed-to-load-.html
Here is cx works for b2b and b2c running parralel on the same instance of Commerce Cloud 1905 with sample manifest.json - https://www.sap.com/cxworks/article/435949087/Choosing_Which_Storefront_to_Use_for_Your_SAP_Commerce_Cloud_Solutionbut according...
Thank you! that worked. What a shame that there is no info about it in documentation nor official tutorial https://www.sap.com/cxworks/article/486232623/Build_and_Deploy_Your_First_SAP_Commerce_Cloud_Project
