Thanks @gdamstra ,
I will be offline shortly due to timezone - I will pick up your response in the morning (about 8 hours).
In the meantime firstly, I assume the field type of the card is in is a Yes/No in SharePoint? See comment below.
When you say you have added a Text Input to the card, is this a Label and I assume it shows true/false?
Now for the rest of it
The toggle has a value Parent.Default for OnChange
You do not need anything OnChange unless you are triggering an another action from it - suggest you delete this as this setting does nothing (may even be an issue)
Parent.Default for Default. For last one a exclamation mark is shown ...
What is the error shown here? It sounds like it may be a different field type
For the Card, some properties are set and/ or has been changed.
Default is now ThisItem.field_name,
No issues here
Update = Toggle2.Value.
Should work if Yes/No field in the List