If then output not working in UNIX SAS

Piece of code on Unix Server is not working, but works on PC SAS. When executed in UNIX SAS, the output datasets pc_pf_yes_1 and pc_pf_no_1 both have 0 observations, but no error is observed. In PC SAS, the code works fine and populates the datasets as intended.

The below datastep is within a macro.

data pc_pf_yes_1 pc_pf_no_1;
    set pc_&month._2;
    if primary_flag = "Y" then output pc_pf_yes_1;
    else if primary_flag = "N" then output pc_pf_no_1;
run;

primary_flag is a binary variable with values Y and N, stored as a string length 1. &month. is a macro variable that stores a month name for data selection.

Is there a quirk with UNIX SAS within a macro that I don't know about?