The *PSSR subroutine handles is called whenever an exception occurs within your program, irrespective of the cause.
The INFSR() keyword for the file allows you to define an exception handling subroutine that is to be executed whenever an exception error occurs for the file.
Specifying INFSR(*PSSR) means that you want the “standard” *PSSR subroutine to handle the file exception which it would do by default – that’s the reason why *PSSR is handling the exceptions for your other files.
If you only want exceptions handled for the specific file then give the subroutine a name other than *PSSR, for example “FileErrSr” and assign that with INFSR(FileErrSr).
However, you would still get the other file exceptions being handled by *PSSR (unless you removed it). If you wanted to keep your *PSSR and not have it handling errors for the other files then create an empty subroutine called something like “IgnoreFileErr” and assign INFSR(IgnoreFileErr) to those files.
Hope it helps