I have a formulas that doesnt automatically compute the formula there is a change in one of the input.

There are 3 tabs, A, B, C

A is the tab which has the SUMPRODUCT formulas.
This formulas reference to data in tab B.

Tab B has a column which takes data from Tab C to generate an output.
This output will be used by tab A.

I realised that if I update the information in tab C, there formulas in tab A doesnt automatically get updated.

I search in the internet and someone mentioned that this could be due to the fact that tab A doesnt know that they need to recomputed when there is a change in tab C.

Anyone know how to make tab A re-compute the data when there is a change in tab C?

I have attached the sample mentioned here in this tread.
The sample is working but not at my actual excel.

Not sure why is it not working in my actual cell?
Any way to push the formulas in tab A to auto-update when there is a change in tab C?


Updates:
I realised that if I do a Ctrl + Alt + Shift + F9, the cells will be updated.
However, is there any thing I can do to make it auto-updates without the need to manually refresh the table?

Many thanks for the assistance.