Display a web app into a web app

Targets Web
1

Two months ago, I was able to display a Xojo web app into another Xojo web app. I used this feature
Self.Security.FrameEmbedding = WebAppSecurityOptions.FrameOptions.Allow
in my calling app.

With the new Xojo version, I have tried this with a site that I know can be embedded and it works fine (http://www.ml6.tech).

When I try to do the same with a Xojo app, it shows me the message: “Cannot reach this page”.

Is it the new Xojo version or I have to do something else?

Thanks for help.