Sounds like you have a multi step process to work through. You need to check for the initial Window itself... once it shows up, there is apparently additional processing that is being done and so you need to wait for that information to be completed.
I'm not sure why you're getting the form.Exists as false initially... my guess is, perhaps, that the Group Index (the second parameter in WaitWindow) needs to be more specific. You are specifying, with the -1, that you want TC to disregard the group index. It is possible, then, that there are other windows with the same WndClass and WndCaption that are being created.
Question: Is there a reason why you are not using NameMapping and Aliases for working with these objects? You can more granularly define and and detect objects using those tools rather than being dependent upon the more generic designations in WaitWindow.
As to why it works in TC9 and not TC11, can't answer that.
