When editing string properties with UiHint.TextArea the cursor jumps to the end of the text

Steps to reproduce

When editing string properties with UiHint.TextArea the cursor jumps to the end of the text from time to time. It seems to be related to when the page is autosaving.

Go to for example to "Alloy plan" in an Alloy Forms and MVC site and to "edit on page". Click on the TestLongString property and then write some text in the popup. 

Move your cursor somewhere in the middle of the text and keep on writing. Soon you will see the cursor jumping to the end of your text.

How the property is defined:

[Display(

            GroupName = SystemTabNames.Content,

            Order = 330)]

[UIHint(UIHint.Textarea)]

           public virtual string TestLongString { get; set; }

And rendered on the template like:

Forms:

<EPiServer:Property runat="server" PropertyName="TestLongString"></EPiServer:Property>

MVC:

@Html.PropertyFor(x => x.CurrentPage.TestLongString)