Multi Select Checkbox not getting unchecked

[Villicus]

Hi, I'm new to power apps and I saw this video on how to do a multi select checkbox, (3) Multi Select Checkbox in Power Apps - YouTube.

However the issue I have is that when you clear the collection my checkboxes still remains ticked. This does not occur in the video. Any fixes for this? 

As you can see when I click the button it should clear the collection and it does but the checkbox still remains ticked why? 

[WarrenBelz]

Hi @Villicus ,

I assume that the checkboxes are in a Gallery - what is the Items of this Gallery and the Default of the checkboxes and what code do you have on the button (all in Text please)

[Villicus]

Hi,

yes I have the checkboxes in a gallery, 

It is from the auto generated datacard when you import from sharepoint, 
In the datacard
Default: CategoryData (its a collection)

Update: CategoryData

Gallery inside the datacard

Default: did not put any text inside

Items: Choices([@IncidentNotiForm].Category)

Checkbox codes:

OnCheck: Collect(CategoryData,ThisItem)

OnUncheck: Remove(CategoryData,ThisItem)

Text: ThisItem.Value

[Villicus · Accepted solution]

Hi I took your advice and started researching for the default of the checkbox to see how it affects the ticked or unticked and I solved the issue. 
The default of the checkbox I used this code:
If(ThisItem in (collectionName), true, false)

Thank you for your time.