I'm doing form like this:

Class MyModel
{
MyPageType CurrentContent {get; set;}
}

cshtml:

@model MyModel

                @using (Html.BeginForm("myMethod", "myController", FormMethod.Post, new { role = "form", id = "myId", enctype = "multipart/form-data", onsubmit = "submitForm();" }))


class myController: PageController<MyPageType>

public ActionResult myMethod(MyModel model)
{
...
}

In 12.15 everything was working as intended, current content was passed correctly.

In 12.17.1 and 12.18 current content is null.

To make matters worse this is on prod and i cannot reverse to veresion 12.15 because of database version.