{paraphrased code}

That's all very well but it makes it much harder for us to help you. Here's my SSCCE which does not reproduce your described problem.

use strict;
use warnings;

use Test::More tests => 1;
use Test::NoWarnings;

use JSON;

my $text = 'file.jpg|fileid|no_file&param_two=1|1|2|2';

eval {
    my $temp = from_json ($text);
} or do {
    print "# Not JSON\n";
};
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