FRS - Does RelativeMember Function work on Prompted AccountingPeriod?

Summary

FRS - Issue with period-to-period comparison on prompted values

Content

I am creating a Period-to-Period Financial comparison report, where Accounting Period needs to be prompted. Accounting Period appears in the column of the dimension layout, say at Column A where the value is prompted. At column B, I tried to apply the function "Relative to Same as Col A offset by -12". But at run time, it is not calculating the offset - so if I select Accounting Period parameter to Apr-20 period, both column A and B come up with Apr-20 whereas the expectation was to have Apr-20 vs Apr-19.