flow – Sharepoint String Column being set as boolean

I have a PowerApp that submits all fields to a PowerAutomate script via JSON. For my Yes/No fields, I set the value of the JSON objects to the strings “Yes” or “No” rather than passing them as boolean.
In my PowerAutomate flow I define the schema of the ParseJSON action with these fields listed as “string”. Then I update a SharePoint List (actually a new doc in a document repository) with these fields. All the columns are defined there as strings (NOT boolean).
Yet, 7 of my 13 Yes/No values get set as boolean (true/false). The other 6 get set as strings (“Yes”/”No”).

I tried adding a space or even a period at the end of the strings in the JSON. It’s still misbehaving and converting some of them to boolean. And it’s always the same fields.
What the hell is happening here???

Here are the fields as defined in SharePoint (with names changed to protect the innocent):
Field1 is getting converted to boolean while Field2 is processing correctly as strings of “Yes” or “No”.
{
“columnGroup”: “Custom Intake”,
“description”: “”,
“displayName”: “Field1”,
“enforceUniqueValues”: false,
“hidden”: false,
“id”: “xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”,
“indexed”: false,
“name”: “Field1”,
“readOnly”: false,
“required”: false,
“text”: {
“allowMultipleLines”: false,
“appendChangesToExistingText”: false,
“linesForEditing”: 0,
“maxLength”: 255
}
},
{
“columnGroup”: “Custom Intake”,
“description”: “”,
“displayName”: “Field2”,
“enforceUniqueValues”: false,
“hidden”: false,
“id”: “xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx”,
“indexed”: false,
“name”: “Field2”,
“readOnly”: false,
“required”: false,
“text”: {
“allowMultipleLines”: false,
“appendChangesToExistingText”: false,
“linesForEditing”: 0,
“maxLength”: 255
}
}

Here’s the snippet of the JSON Schema:
{

“Field1”: {
“type”: “string”
},
“Field2”: {
“type”: “string”
},

}

And here’s the snippet of the data passed in as JSON.
{

“Field1”: “No.”,
“Field2”: “No.”,

}

Also, When I manually try to change the value of one of the misbehaving columns in the list (doc repository) to “Yes” or “No”, it reverts back to boolean.

Please help me keep my remaining hair…..