Value evaluation in Qlik Sense function

[ABNoel_Travelers]

Good Evening.. have an interesting one.

I have a field that has been loaded using the YearName() and has a value in it of 2020-2021. I'm attempting to use that in a formula for a KPI in the visualization and I get an error I can't seem to get around. If I hard set it to the value with '2020-2021' for the MaxString value the formula works.

Here is what the formula string looks like:

sum({$<ContractFiscalYear={$(=MaxString(ContractFiscalYearCurrent))}>} tot_dbus * [All Purpose Cost])

If I hard set it to the value with '2020-2021' for the MaxString value the formula works just fine.

The value of the MaxString(ContractFiscalYearCurrent) = 2020-2021

The value for ContractFiscalYear is also 2020-2021

The value of variable [All Purpose Cost] is .568

I get this error in the formula:

Error in expression

Error in set modifier ad hoc element list:',', or ')' expected

sum({$<ContractFiscalYear={2020-2021}>} tot_dbus * [All Purpose Cost])

My only thought is the "-" in the value the YearName() creates (2020-2021)  is creating a problem since if I hard set it with quotes around it the formula works. 

Any thoughts or ideas would be greatly appreciated.

[Digvijay_Singh]

Check this may be - 

sum({$<ContractFiscalYear={'$(=MaxString(ContractFiscalYearCurrent))'}>} tot_dbus * [All Purpose Cost])