Linked workbook data not updating

This process using linked workbooks was designed before I started at this org but we are in the process of modernising it with an internally developed portal. We have an immediate need to resolve the issue for now. So i'm not identified I have simplified the below.

We have a main distribution centre(referred to as MDC), whose inventory is fed by edge DC's(referred to by EDC)

We have a master inventory spreadsheet, its a beast that has a sheet for the MDC and one for each EDC.

The MDC sheet has a column for each EDC and product we have, then inventory manager will place a value on the day a product from an EDC need to ship to arrive at our MDC. The EDC's tab/sheet has a link in every cell to the MDC to auto update. Managers of the EDC's have view access to this workbook and its hosted in SharePoint Online.

Each EDC has a separate workbook with a workbook link back to their tab in the master inventory workbook.

The issue we are finding, if the inventory manager updates the MDC tab, the value comes across to the EDC's tab as expected. We are finding that linked value is not coming across to the separate EDC's workbook despite the workbook link refreshing.

If I open up the master inventory spreadsheet and break one of the EDC cell's formula and put something into the cell then the separate EDC workbook updates as expected.

Again, I know this process is convoluted hence us modernising it.