How about showing us a small sample of the data that fails? Use the following code as a template and show us the output you get and what you expected.

use strict;
use warnings;

my @bitter = ('x=y', 'z=p=q');

foreach (@bitter) {
    my ($first, $second) = split /=/;
    
    print ">$first< [$second]\n";
}
[download]

Prints:

>x< [y]
>z< [p]
[download]