Typescript XOR type error

xor.ts

type Without<T, U> = { [P in Exclude<keyof T, keyof U>]?: never };

// this type is NOT work as expected
type XOR<T, U> = (T | U) extends object ? (Without<T, U> & U) | (Without<U, T> & T) : T | U;
// this type is work as expected
type XOR<T, U> = (T | U) extends Object ? (Without<T, U> & U) | (Without<U, T> & T) : T | U;

interface IValueWillChange<T> {
    object: any;
    type: "update";
    newValue: T;
}

type xorType = XOR<{all?: any}, string>

function calculateRelativeStatsTotals(
    change: IValueWillChange<xorType>
): IValueWillChange<xorType> {
    var newValue = change.newValue
    var object = { a: 1 }
    var type = 'update' as 'update'

    // there typescript compilator show an error for first variant of XOR type
    if (newValue.all) {
        console.log(1)
    }
    
    return {
        newValue,
        object,
        type
    }
}