TableView not working after leaving and coming back to the view - ios

Question

I am puzzled by the behavior of tableView if you leave their view and come back.
I have a screen with one tableView in it that works when I first enter the view. Adding, removing, and updating table cells work. However, when I press a button to segue into the next view and immediately come back, the tableView no longer works. The code that is supposed to execute ( tableView.reload() and all the associated methods) run as they should. However, the screen does not get updated even though internally the arrays get updated, and reload gets ran and executes the code that should update the screen( that is, tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell runs jus fine).
What am I missing? Does tableView require any special treatment if I leave the view and come back to ti?
Thanks.
Edit:
The code for the class where the tableView is something like:
class DebugViewController: UIViewController, UITableViewDataSource, UITableViewDelegate{
#IBOutlet weak var table: UITableView!
var array = [M]()
override func viewDidLoad() {
super.viewDidLoad()
self.searchbar.delegate = self
self.table.delegate = self
self.table.dataSource = self
search_view = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "Search_view") as? SomeViewController
}
func tableView(_ tableView: UITableView, cellForRowAt indexPath: IndexPath) -> UITableViewCell {
guard let cell = tableView.dequeueReusableCell(withIdentifier: "cellManage") as? TableCellManage else { return UITableViewCell() }
let idx = indexPath.row
let value = array[idx]
cell.lbl_time.text = value.month
cell.lbl_background.text = value.color
return cell
}
func tableView(_ tableView: UITableView, heightForRowAt indexPath: IndexPath) -> CGFloat {
return 130
}
func tableView(_ tableView: UITableView, numberOfRowsInSection section: Int) -> Int {
return self.array.count
}
#IBAction func tapped_addsongs(_ sender: Any) {
self.present( search_view, animated: true, completion: nil)
}
}

Answer 1

Where is the tableView.reload() part? The issue might be generated because you're trying to update the table in a background thread. All UI Updates must be done in main thread:
func someFunc() {
...
DispatchQueue.main.async {
tableView.reload()
}
...
}

Answer 2

After looking at pretty pictures of the life cycle of apps and googling I found the issue and the solution.
The problem was that I had listeners set up to update my table view in a troublesome way. Specifically, I was using the viewDidAppear/viewDidDisappear to bring up and down the listeners, and there was some conflict in the code that managed the state because of this.
Instead, I now bring up the listeners on viewDidLoad. They stay active, regardless of how many views are pushed (within reason, but I only push one), and update my tableview so that when I come back to that view everything is already updated. I don't even see the updates happening, they happen before I get to my view. As for detaching the listeners there is a handy-dandy function I did not know about until 5 minutes ago: deinit. This is the equivalent of destructor in Swift, so I detach my listener when my class object for this view is released from memory.
That solves my issue...and increases performance and I no longer have dangling connections for not managing the listeners well. So a win-win-win.
Thank you all for trying to help! I hope this helps other folks.