Ionic capacitor app not working as expected in ios build

I have an Ionic Angular Capacitor app working good in web and in android build, but in Ios simulator not working as expected and I can’t put my hand on the problem. I have http request to login which sends username and password as data:

  next: (authenticateResult: LoginResponseModel) => {
    console.log('result ', authenticateResult); // line#1
    // extra code to validate the response
    this._router.navigateByUrl('/tabs', { replaceUrl: true }); // line#2
error: (err) =>{
  console.error("something happened ..") // line#3
  console.error("error ",err); // line#4

when debugging with Ios simulator and safari web inspector: http request returns status code 200 and the expected response returned. line#1 is reached and put in console log line#2 is never executed then line #3 is executed line#4 is executed and prints error as: TypeError: Argument 1 (‘blob’) to FileReader.readAsText must be an instance of Blob

and if password contains @ character it is sent to the server as %2540 so the login response never returns true
I suspect xcode not able to convert response to js so I removed all the code in subscribe next part, but it still raise an error. The weird thing that it enters next part and then jump into error part in subscribe, also the error message shows dealing with blob and files which is not the case here.

im having the same problem. it seems to not be reaching the next method at all. im not sure how to handle this.