Error: Imported outputs omit more outputs that we know of
To send transactions using a view-only wallet and an offline wallet, I follow the doc - https://github.com/monero-ecosystem/monero-javascript/blob/master/docs/developer_guide/view_only_offline.md - and made one successful transaction. It was on chain and I can search it on the block explorer.

This is my code:
```
    // create and sync view-only wallet without spend key
    const viewOnlyWallet = await connectToWallet();
    await viewOnlyWallet.sync();

    // view-only wallet: export outputs
    const outputsHex = await viewOnlyWallet.exportOutputs();

    // create offline wallet
    const offlineWallet = await restoreWalletFull(privateSpendKey, from);

    // offline wallet: import outputs
    await offlineWallet.importOutputs(outputsHex);

    // offline wallet: export key images 
    const keyImages = await offlineWallet.exportKeyImages();
    console.log(JSON.stringify(keyImages))

    // view-only wallet: import key images
    await viewOnlyWallet.importKeyImages(keyImages);

    // view-only wallet: create unsigned tx
    const unsignedTx = await viewOnlyWallet.createTx({
        accountIndex: 0,
        address: to,
        amount,
    });

    // offline wallet: sign tx
    console.log(unsignedTx.getTxSet().getUnsignedTxHex()) // prints a hex string
    const signedTxHex = await offlineWallet.signTxs(unsignedTx.getTxSet().getUnsignedTxHex());
    
    // view-only wallet: submit signed tx
    const txHashes = await viewOnlyWallet.submitTxs(signedTxHex);
    console.log(txHashes)
```

But then from my second attempt on, it stuck at `adding trust anchor:` before throwing the error:
```
    Imported outputs omit more outputs that we know of
      211 |       let callbackId = GenUtils.getUUID();
      212 |       LibraryUtils.WORKER_OBJECTS[objectId].callbacks[callbackId] = function(resp) {  // TODO: this defines function once per callback
    > 213 |         resp ? (resp.error ? reject(new MoneroError(resp.error)) : resolve(resp.result)) : resolve();
          |                                     ^
      214 |       };
      215 |       worker.postMessage([objectId, fnName, callbackId].concat(args === undefined ? [] : GenUtils.listify(args)));
      216 |     });
```
or this error:
```
Failed to get height

      337 |   static _validateRpcResponse(resp, method, params) {
      338 |     if (!resp.error) return;
    > 339 |     throw new MoneroRpcError(resp.error.message, resp.error.code, method, params);
          |           ^
      340 |   }
      341 |   
      342 |   _setFakeDisconnected(fakeDisconnected) { // used to test connection manager
```
console.log(JSON.stringify(keyImages)) prints an empty array: []. I don't know if it has anything to do with the error. If not, what are likely causes of this error and what fixes it? 