PyCryptodome Error: MAC Check Failed while using OCB after sending a json with sockets

I am trying to implement Aes encryption with the OCB mode, when i do both encryption and decryption in a single file everything works perfectly, however if i send a json with nonce cyphertext and a tag through a socket i always get a "MAC check failed" error even thou the jsons are identical. Here's encryption and decryption functions respectively.

def enc_pic(data):
    cipher = AES.new(key, Amode, nonce=get_random_bytes(8))
    data = pickle.dumps(data)
    ciphertext, tag = cipher.encrypt_and_digest(data)
    json_k = ['nonce', 'ciphertext', 'tag']
    json_v = [b64encode(x).decode('utf-8') for x in (cipher.nonce, ciphertext, tag)]
    data = json.dumps(dict(zip(json_k, json_v))).encode("UTF-8")
    print(data)
    return data

def decr_pic(data):
    try:
        b64 = json.loads(data.decode("UTF-8"))
        print(b64)
        json_k = ['nonce', 'ciphertext', 'tag']
        jv = {k: b64decode(b64[k]) for k in json_k}
        cipher = AES.new(glob.aes_key, AES.MODE_OCB, nonce=jv['nonce'])
        plaintext = cipher.decrypt_and_verify(jv['ciphertext'], jv['tag'])
        res = pickle.loads(plaintext)
    except (ValueError, KeyError) as e:
        res = "Incorrect decryption"
        print(e)
    return res