A user reported to me that they are unable to create a PSBT with a legacy watchonly wallet when they use the GUI. They get an error "The amount exceeds your balance".

I think the issue is that the GUI will retrieve the wallet's balance via `AvailableCoins` before calling `CreateTransaction`. This call to `AvailableCoins` is resulting in fewer coins being returned with recent changes to how `AvailableCoins` works, particularly with additional filtering of spendable coins and preset coins.

***

Note that this does not effect descriptor wallets. A workaround for this issue is to switch to using descriptor wallets. An existing legacy wallet can be turned into a descriptor wallet using the `migratewallet` RPC. However many watchonly legacy wallets are likely the result of importing descriptors via `importmulti`. For such wallets, I recommend creating a new descriptor wallet and re-importing the descriptors.
}
        } else if (model->wallet().privateKeysDisabled()) {
            ui->sendButton->setText(tr("Cr&eate Unsigned"));
            ui->sendButton->setToolTip(tr("Creates a Partially Signed Bitcoin Transaction (PSBT) for use with e.g. an offline %1 wallet, or a PSBT-compatible hardware wallet.").arg(PACKAGE_NAME));
        }
        
        QSettings settings;
        if (settings.value("nSmartFeeSliderPosition").toInt() != 0) {
            
            
            int nConfirmTarget = 25 - settings.value("nSmartFeeSliderPosition").toInt(); 
            settings.setValue("nConfTarget", nConfirmTarget);
            settings.remove("nSmartFeeSliderPosition");
        }
        if (settings.value("nConfTarget").toInt() == 0)
            ui->confTargetSelector->setCurrentIndex(getIndexForConfTarget(model->wallet().getConfirmTarget()));
        else
            ui->confTargetSelector->setCurrentIndex(getIndexForConfTarget(settings.value("nConfTarget").toInt()));
    }
}
SendCoinsDialog::~SendCoinsDialog()
{
    QSettings settings;
    settings.setValue("fFeeSectionMinimized", fFeeMinimized);
    settings.setValue("nFeeRadio", ui->groupFee->checkedId());
    settings.setValue("nConfTarget", getConfTargetForIndex(ui->confTargetSelector->currentIndex()));
    settings.setValue("nTransactionFee", (qint64)ui->customFee->value());
    delete ui;
}
bool SendCoinsDialog::PrepareSendText(QString& question_string, QString& informative_text, QString& detailed_text)