Multiselect with Grouped Data, select all options

[Rakasch]

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CodeSandbox Case (Bug Reports)
https://codesandbox.io/s/grouped-dropdown-vxzwf?file=/src/MultiSelectDemo.vue

Current behavior
I'm using Multiselect Component with grouped data and optionValue="id".
It's working as expected if I select single options.

But if I check the "mark all" checkbox, its ignoring the optionValue and optionLabel.
It just inserts the whole objects into the modelValue. And the Labels are all null.

Expected behavior
Selecting "mark all" should have the same behaviour as selecting single options.

Minimal reproduction of the problem with instructions
Use Multiselect Component with grouped data and optionValue.
Select "all" options.

• Vue version: 3.X

• PrimeVue version: 3.4.X

• Browser: [all | Chrome XX | Firefox XX | IE XX | Safari XX | Mobile Chrome XX | Android X.X Web Browser | iOS XX Safari | iOS XX UIWebView | iOS XX WKWebView ]