Blob message does not retain correct buffer length

[seph14]

In the sending part, I'm sending a 384 byte array, but when taking the data out it reported 1408 bytes.

mClient.Send("/skeleton", rawbuffer, rawbuffer.Length);

void SkeletonCb(OscMessageValues data) {
        // read as byte
        data.ReadBlobElement(0, ref mRawBuffer);
}

the 2 RawBuffers have different length, but the first 384 byte received seems to have correct data in it.