Also note that the Perl language uses different operators to compare strings for equality or inequality:   eq, ne, cmp ... see perlop.

Operators such as ==, !=, <=&t; always perform numeric comparison.   Your use of that operator, then, could be part of the problem.

And, by the way, this is a very-conscious design decision made by the original architect(s) of the language.   Perl has always been oriented toward the processing of text files, and this strategy makes it possible to precisely specify, say, sorting operations and so forth when the data being processed (in the text ...) “is a number.”