Locking a sum formula while still allowing users to insert and delete rows

Im in a pickle.

At my work we use spreadsheets split into weeks. Each weeks data is summed in a formula. What we are having issues with is users deleting the sum formulas accidentally and not realising it. To solve this we have added in a row above the sum formula and the top most row the formula takes into account and greyed them to make them stand out. We then lock these 2 new rows aswell as the sum formula. My issue is we have to allow the users to insert and delete rows as the data can grow and shrink from week to week and month to month. This poses a problem because other than accidentally deleting formulas my staff now tend to add their extra lines they need below the grey and above the sum formula which breaks the sum formula so it is no longer anchored.

Is there a way i can make it impossible for my staff to insert and delete rows inbetween the grey line and sum formula for each week.

I am unable to use macros in this situation as the company is not a fan.

FINGERS CROSSED

EXAMPLE.xlsx