iOS 10.3.3导航栏未显示所有按钮

我有一个带有3个按钮的UINavigationBar，它在有11个iOS的iPhone7上运行良好，但iPhone5 10.3.3在导航栏中只显示了三个按钮中的右侧

这里怎么了

    private func setupNavMenuButtons() {

    navButtonTimeframe.addTarget(self, action: #selector(timeframeMenuHandler), for: UIControlEvents.touchUpInside)
    navButtonTimeframe.setTitle(TIMEFRAMES[InAppProperties.sharedInstance.portfolioTimeframeMode], for: .normal)

    let timeframeBtn = UIBarButtonItem(customView: navButtonTimeframe)

    let refreshNav = UIBarButtonItem(barButtonSystemItem: .refresh, target: self, action: #selector(menuRefreshHandler))

    navButtonConvert.addTarget(self, action: #selector(convertMenuHandler), for: UIControlEvents.touchUpInside)

    var image : UIImage
    switch InAppProperties.sharedInstance.convertSymbolWatch {
    case PreferencesHelper.BTC_SYMBOL:
        image = (UIImage(named: "convert_btc_portfolio")?.withRenderingMode(.alwaysOriginal))!
    case PreferencesHelper.ETH_SYMBOL:
        image = (UIImage(named: "convert_eth_portfolio")?.withRenderingMode(.alwaysOriginal))!
    default:
        image = (UIImage(named: "convert_usd_portfolio")?.withRenderingMode(.alwaysOriginal))!
    }

    navButtonConvert.setImage(image, for: .normal)
    let convertNav = UIBarButtonItem(customView: navButtonConvert)

    self.navigationItem.rightBarButtonItems = [refreshNav, convertNav, timeframeBtn]
}

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将该行添加到两个自定义项（除.refresh外）：

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它正在工作。

尝试通过设置

背景色来调试按钮的框架。

每个屏幕的宽度都不同，在小屏幕中相应地管理按钮。框架没有其他问题

 navButtonTimeframe.frame = CGRect(x: 0.0, y: 0.0, width: 40, height: 40)