Context: I am talking about a new program from Microsoft for Microsoft Teams based app development called "SLATE". This program requires 6 weeks fixed timeline for the "Build" phase and 2 weeks fixed timeline for "Envision" phase. Microsoft development partners who are involved in these phases, need to provide detailed documents (eg: Detailed SOW before starting Build phase) to Microsoft, to the engagement with the partner and Microsoft customer to be approved. On successful delivery after the 6 weeks of build phase - Microsoft pays the money to the partner. Technically the Microsoft customer get the software for free. Microsoft gets Azure, O365 costs from the customer, since the software was developed to use such technologies. Cost of the Build phase is around USD 25000, which will be paid to the partner who develops the solution and the Microsoft partner is entitled to get support from Microsoft product development teams.
Problem: Our team tried to do this in agile methodology which is consist of 2 week sprint - but realized that after 2 week sprint demo, we started receiving changes from the Microsoft customer to whom we are building this solution. But Microsoft is saying that the SOW is fixed and can not be changed.
Considering the 6 weeks fixed timeline and the SOW cannot be changed, can we say: we can only use "waterfall" methodology for such projects engagement?