Memory crash at String._bridgeToObjectiveCImpl()

I'll describe my crash with an example, looking for some insights into the reason why this is happening.

@objc public protocol LauncherContainer {
  var launcher: Launcher { get }
}

@objc public protocol Launcher: UIViewControllerTransitioningDelegate {
  func initiateLaunch(url: URL, launchingHotInstance: Bool)
}

@objc final class LauncherContainer: NSObject, LauncherContainer, TabsContentCellTapHandler {
...
  init(
    ...
  ) {
    ...
    super.init()
  }

  ...

  //
  // ContentCellTapHandler
  //
  public func tabContentCellItemDidTap(
    tabId: String
  ) {
    ...
    launcher.initiateNewTabNavigation(
      tabId: tabId      // Crash happens here
    )
}

public class Launcher: NSObject, Launcher, FooterPillTapHandler {
  public func initiateNewTabNavigation(tabId: String) {
     ...
  }
}

public protocol TabsContentCellTapHandler: NSObject {
  func tabContentCellItemDidTap(
    tabId: String,
}