Redirecting Opc payments with SEO-friendly URLs enabled

[Aghas-Mh]

One Page Checkout with enabled SEO-friendly URLs and redirection payment method does not work.
Video showing the problem

[Aghas-Mh]

To fix this, you can add an entry to Presentation\Nop.Web\Infrastructure\RouteProvider.cs

        endpointRouteBuilder.MapControllerRoute(name: "OpcCompleteRedirectionPayment",
            pattern: $"{lang}/checkout/OpcCompleteRedirectionPayment",
            defaults: new { controller = "Checkout", action = "OpcCompleteRedirectionPayment" });

And in Presentation\Nop.Web\Controllers\CheckoutController.cs
change inside the function (line:2012) OpcConfirmOrder(bool captchaValid)

if (paymentMethod.PaymentMethodType == PaymentMethodType.Redirection)
{
    //Redirection will not work because it's AJAX request.
    //That's why we don't process it here (we redirect a user to another page where he'll be redirected)
    var language = await _workContext.GetWorkingLanguageAsync();

    //redirect
    return Json(new
    {
        redirect = $"{_webHelper.GetStoreLocation()}{language.UniqueSeoCode}/checkout/OpcCompleteRedirectionPayment"
    });
}

[Aghas-Mh]

Although the problem does not end there.
For some reason, the old redirect response is cached and always redirects to the same completed transaction. Only after hard-coded clearing of the page cache does the situation improve.
https://drive.google.com/file/d/1Phd1H5F4djVS-RCU4YK5TAPt_qLIFP0b/view?usp=sharing

[RomanovM]

Couldn't reproduce the issue, just tried with two different plugins. Redirection works as it should.