1. I realized that you're using Combo box instead of dropdown list ,these 2 controllers are little different in use.
but I checked in my sharepoint list ,it goes correctly, if it still does not work ,you can try dropdown control as a backup
2. if you're using dropdown , i need to remind you that the LookUp function has 3 paremeters: LookUp( Table, Formula [, ReductionFormula ] )
in your formula , you just has 2 parameters, which means:" If you don't use this parameter, the function returns the full record from the table. "
so , if you're using dropdown , the code would be:
If(DataCardValue*.Value, LookUp(Choices(****) ,Value="***", Value),LookUp(Choices(****) ,Value="choB",Value))
just in case , make sure the combo box or the dropdown control has the correct item property
let me know whether it's working
BTW: what do you mean you cannot see the toggle button is view mode , in the view mode in sharepoint , we can just see the toggle control's value,true or false,we cannot see the control itself