PHP Deprecated: strpos()

I got a PHP notice while debugging a Forminator form:

class ForminatorHooksDebugger {

    private $entry_id = 'N/A';

    public function __construct() {
	add_filter( 'forminator_replace_form_data', array( $this, 'replace_form_data' ), 10, 3 );
    }

public function replace_form_data( $content, $data, $original_content) {
        error_log( "Hook: forminator_form_replace_form_data - Form ID: " . $data['form_id'] );
        $this->log_current_entry( $data['form_id'], "replace_form_data", $data);

    }

    private function log_current_entry( $form_id, $hook_name, $entry = null ) {
        if (is_null($entry)) {
            error_log( "Current Entry (within " . $hook_name . "): Entry is not available at this point." );
            return;
        }

        if (is_object($entry) or is_array($entry)) { 
          error_log( "Current Entry (within " . $hook_name . "): " . print_r( $entry, true ) );
        } else {
          error_log("Current Entry (within " . $hook_name . "): Entry format is unknown.");
          error_log(print_r($entry, true));
          return;
        }       

    }
}

new ForminatorHooksDebugger();

The Notice is:

[06-Feb-2025 07:52:59 UTC] PHP Deprecated: strpos(): Passing null to parameter #1 ($haystack) of type string is deprecated in /public_html/wp-content/plugins/forminator/library/helpers/helper-fields.php on line 1138

There are a multi-upload field and some hidden fields in the form.