OnVisible Not Firing

[Anonymous]

I have a rather complex PowerApp that utilizes a multi screen form. I keep runnning into an issue where the OnVisible events will not fire correctly. They usually fire the first time correctly, but if I navigate away from the page and come back later - they will not fire a second time. I have to either restart the entire app or cut the code from the property, navigate away, and then navigate back and then paste the code back in to get the code to fire correctly on the next screen load.

It makes no sense as it works correctly sometimes and other times does not fire at all. This only started happening after I added in a process that collects some data on screen visible into a collection. However, this is not the only thing that is not working - everything including simple updatecontext variable statements are not working the second time around.

[stapes]

Yes. I found this too. Especially frustrating as the OnVisible property of the first screen does not fire at all in the debugger until you navigate away & return, resulting in having to collect all the data in the AppStart.

[Anonymous]

I know this is an old post, but I'm posting this tip because my team of colleagues recently had this issue and I'd like to contribute a searchable solution.

We had a grouped set of objects named "Cancel_Group" with the Visible setting set to a variable named "CancelGroup" and none of our UpdateContext({CancelGroup: true}) or UpdateContext({CancelGroup: false}) were working. We found that the variable cannot be the same as the object reference name and that the underscore symbol is read as the same, which meant:
"CancelGroup" = "Cancel_Group" the same as "CancelGroup" = "CancelGroup".

Once we changed the variable to "CancelGroupVis", the visibility variable worked.

We also tested this by going to other grouped and ungrouped objects and renaming them and found that this was the case in all scenarios. 

[MengtingXie]

I have the same issue, when I navigate the screen the big part of the codes in OnVisible do not fire, but if I navigate to another screen and then navigate back to this problematic screen, the codes in OnVisible will fire. Super annoying. 2023 I still have the same issue. My app is quite complex today, maybe the app get confused.

[LimeLeaf]

I thought I had the same issue with OnVisible not firing in regards to the DefaultSelectedItems property of comboboxes. But for me it turns out it was about the order I was executing my steps. (Clear - collection , Collect - collection, Reset - combobox)

Anyway I want to share it in case it might help someone else:
I have a multi screen app in place with several combo Boxes. All of them are feeded with DefaultSelectedItems from multiple collections. OnVisible of each screen I'm clearing and refilling all these collections. 

The Issue:
After navigating backwards and forwards in my app I was expecting new values form my DefaultSelectedItems in my comboboxes, as I'am clearing and refilling all these collections OnVisible. But old values where shown as DefaultSelectedItems even the collections where populated with the right and new values. It seems for me like the comboboxes were not properly reseted OnVisbible of the Screen.

My wrong order of doing things:
1. Reset the Comboboxes
2. Clear the collections
3. Collect / Refill the collections.

Right order of doing things:
1. Clear the collections
2. Collect / Refill the collections.
3. Reset the Comboboxes

The comboboxes had to be reseted after filling the collections because only then new values can be drawn into the DefaultSelectedItems.