Lookupvalue occasionally return blanks when randbetween used

[sperry]

In PowerBI Desktop I have a calculated column to rank a text value;

Rank = rankx(NYNY,NYNY[NHI],,ASC)

This returns unique values.

I have a calculated column to return a random value using rank to generate the lookupvalue 

Name1 = LOOKUPVALUE(NYNY[Surname&NHI],NYNY[Rank],randbetween(1,max(NYNY[Rank])))

Name 1 will randomly generate a blank value..Anyone see why??

NB the source table is a duplicate of another table with a fliter step added.

[v-xjiin-msft]

Hi @sperry,

Without knowing your source table structure and some sample data. It is hard for us to understand your requirement.

Thereby, could you please share us more information like your source table structure and some sample data which can help us repro your issue. Also it will be more helpful if you can share us your desired result based on your sample data. It will give us the right direction.

Thanks,
Xi Jin.