Swift 5.3.2: Object conformed to Objective-C protocol with properties defined as @optional, is always immutable [duplicate]

There is an issue I have in swift with the object type conformed to @objc protocol with the property that is defined as @optional var.

Swift 5.3.2 assumes that optional property is immutable.

import Foundation

@objc protocol Bar {
    @objc var mutableVar: Bool { get set }
    @objc optional var mutableVar2: Bool { get set }
}

func foo(_ object: AnyObject & Bar) {
    var object = object
    object.mutableVar = false // compiles fine
    object.mutableVar2 = false // error: Can not assign to property: 'object' is immutable
}