HttpException:400 Unable to verify your data submission

My log files are filled with these errors

2021-11-19 12:39:42 [27.xxx.xxx.xxx][1958][gi96uqh6atadlbsg2ksjfltd9e][error][yii\web\HttpException:400] yii\web\BadRequestHttpException: Unable to verify your data submission. in /var/www/html/vendor/yiisoft/yii2/web/Controller.php:218

Can't seem to figure out why. As i can't replicate the problem either.

I've read this, but the solution doesn't apply to me as all my forms are created using $form = ActiveForm::begin([]) and i'm not uploading files.

in my <header> i have this

<meta name="csrf-param" content="_csrf-frontend">
<meta name="csrf-token" content="oidpfJVSR28kMxgD4loRdgIs3TCRVITuR6Ly3Z587nLxdgIt-h8XIlFbSECzCEgHUmqaQ9InwaIYzJ2u-ySaIw==">

and because i use $form = ActiveForm::begin([]), for my form there is this hidden field

<form id="form-small" action="/frontend/web/search/" method="post">
<input type="hidden" name="_csrf-frontend" value="oidpfJVSR28kMxgD4loRdgIs3TCRVITuR6Ly3Z587nLxdgIt-h8XIlFbSECzCEgHUmqaQ9InwaIYzJ2u-ySaIw==">

here is my $form = ActiveForm::begin([])

$form = ActiveForm::begin([
        'id' => $model->formName().'-form-small',
        'action' => ['/search/default/id'],
        'method' => 'post',
        'scrollToError' => false,
        'validateOnChange' => false,
        'validateOnSubmit' => true,
        'enableClientValidation' => true,
        'enableAjaxValidation' => true,
        'fieldConfig' => [
            'options' => [
                'tag' => false,
            ],
        ],
    ]);

i also have this JS in my footer. (main.php layout)

<script>
    $.ajaxSetup({
      headers: {
        'X-CSRF-TOKEN': '<?= \yii::$app->request->csrfToken ?>'
      }
    });
</script>

And i DO NOT want to turn CSRF off either.

in my main.php i have this

 'request' => [
            'csrfParam' => '_csrf-frontend',
            'enableCsrfCookie' => false, 
            'enableCookieValidation' => true,
            'cookieValidationKey' => 'frontend-cookie-2021',
        ],

I edited yii/framework/web/Request.php

and added the code below before line 841

echo ' -- start--';
        echo '<br><br><br>';
        print_r($trueToken); 
        echo '<br><br><br>';
print_r($this->getBodyParam($this->csrfParam));
echo '<br><br><br>';
print_r($this->getCsrfTokenFromHeader());
echo '<br><br><br>'; 
echo ' -- end--';
die;

every time i submit my form. the $trueToken token seems to be different. even when i don't refresh the page.

like below

-- start--
S-r869794GPYBi8voh-dXVDFLLWl8GvWhw6Qvn4c7icYu5e6sbCwLq1uf2zzTcQsAINrxuaDLprYYP_NG0Sadg==

b4GMJgf6dmn8H64oljr6uxokFC2WbQeLP4bY_SI-7Pg80Od3aLcmJIl3_mvHaKPKSmJTXtUeQsdg6LeOR2aYqQ==

b4GMJgf6dmn8H64oljr6uxokFC2WbQeLP4bY_SI-7Pg80Od3aLcmJIl3_mvHaKPKSmJTXtUeQsdg6LeOR2aYqQ==
-- end--

Any idea how to fix this? Thank you.