react-native-sodium with PHP's sodium fails at crypto_box_seal_open()

Question

Here's my encrypting flow:

1. I'm creating a key-pair on my iOS device.
2. I send to public key to the server (PHP) via Fetch
3. I create a push-notification on the server and encrypts it with sodium_crypto_box_seal() and sends it sucessfully
4. I receive the notification on my iOS device and try unsucessfully to decrypt the message with crypto_box_seal_open

React-native:

import Sodium from 'react-native-sodium';
let key_pair = { pk, sk } = await Sodium.crypto_box_keypair();
await sendToServer(pk);

-- PHP --

$msg = CloudMessage::fromArray(
  [ 'notification' => $notification,
         "apns" => [
            "payload" => [
                "aps" => [
                    "sound" => 'default',
                ],
            ],
        ]
    ]
);

sendMulticast( $message, $apn_tokens );

Then back in react-native I receive the push-notification

const incomingNotifiction = () => {
try {
   let note = JSON.parse(notification.notification.body.toString())
   note = btoa(note)
   let result = await Sodium.crypto_box_seal_open(note, public_key, private_key)
} catch(e) {
   console.log(e) // prints "FAILS HERE!" 
}
})

crypto_box_seal_open() from node_modules/react-native-sodium/iOS/RCTSodium.m

else if (crypto_box_seal_open(dm, [dc bytes], dc.length, [dpk bytes], [dsk bytes]) != 0)
    reject(ESODIUM,@"FAILS HERE!",nil);

Any idea why the decryption fails? Any help will be greatly appreciated. I've struggled for days now