Why is my array buffer suddenly detaching?

Question

I have the following uWebsockets application:

const app = uWS.App({}).ws("/*", {
  message: (ws, bytes, isBinary) => {
    invariant(isBinary, "Websocket messages must be binary");
    const unpacked = unpack(Buffer.from(bytes));
    const msg = Message.parse(unpacked);
    console.log("AFTER PARSE")
    console.log(bytes);

    if (msg.kind === Codes.Selection || msg.kind === Codes.ClearSelection) {
      const { postId } = msg;
      republishMessage(app, postId, bytes);
      //echoMessage(ws, postId, bytes);
    } else if (msg.kind === Codes.Subscribe) {
      const { postId } = msg;
      handleSubscribe(ws, postId);
    } else if (msg.kind === Codes.CreateHighlight) {
      console.log("BEFORE HANDLER")
      console.log(bytes)
      handleCreateHighlight(app, bytes, msg);
    }
  },
});

// the problematic handler
export async function handleCreateHighlight(
  app: uws.TemplatedApp,
  bytes: ArrayBuffer,
  msg: CreateHighlightMessage
) {
  const { userId, range, postId } = msg;
  logger.info(`Highlight for ${postId} by ${userId}`);
  await db.Page.makeHighlight(postId as PageId, {
    userId: userId as UserId,
    range,
  });
  console.log("BEFORE REPUBLISH");
  console.log(bytes);
  await republishMessage(app, postId, bytes);
}

I've noticed some strange behavior inside the handleCreateHighlight handler. The ArrayBuffer, bytes is valid at the "AFTER PARSE" and "BEFORE HANDLER" console.log points. However, the ArrayBuffer is detached at the "BEFORE REPUBLISH" console.log point.

Why is the ArrayBuffer getting detached, and how do I prevent this from happening? Does this have to do with the fact that I'm using the ArrayBuffer after an await point?

Also for context, pack is a function from the msgpackr library, which is an extremely fast MessagePack serializer/deserializer for Javascript.