Using master (98958c81f5065a5de13699d46995d278ecb6709e) with Qt `5.12.3` (also tested with depends) with multiple wallets available. None are shown in the `Open Wallet ->` menu in the gui. The wallets can be loaded from the console, bitcoin-cli etc.
updateWindowTitle();
    rpcConsole = new RPCConsole(node, _platformStyle, nullptr);
    helpMessageDialog = new HelpMessageDialog(node, this, false);
#ifdef ENABLE_WALLET
    if(enableWallet)
    {
        
        walletFrame = new WalletFrame(_platformStyle, this);
        setCentralWidget(walletFrame);
    } else
#endif 
    {
        /* When compiled without wallet or -disablewallet is provided,
         * the central widget is the rpc console.
         */
        setCentralWidget(rpcConsole);
        Q_EMIT consoleShown(rpcConsole);
    }
    
    setAcceptDrops(true);
    
    
    createActions();
    
    createMenuBar();
    
    createToolBars();
    
    if (QSystemTrayIcon::isSystemTrayAvailable()) {
        createTrayIcon();