and it doesnt print that text (aaaaaaaaaaaa) when the perl file is executed.

If it doesn't, then print is broken in Perl and no one has noticed all these years. print is probably not broken in Perl.

It's more likely that that (unbuffered) print occurs before you've finished printing HTTP headers to the browser, so it's getting lost somewhere that you don't see it. Run your program from the command line instead to see that, indeed, print works in Perl as it has worked for 20 years.