I don't know the answer to this, but I know enough about excel to know that it might not have anything to do with your computer's specifications.

I know that Excel has a bunch of heuristics to determine where/when it decides to recalculate a given cell's value, and that the recalculation itself might be slow if the spreadsheet is complicated, for instance if there are a lot of references in the chain of calculation.

Perhaps start here and see if anything rings a bell:
https://docs.microsoft.com/en-us/office/client-developer/excel/excel-recalculation