Foundry 1 sites opened after upgrading to Foundry 2 messed up?

This is just a quick initial question, to see if anyone else has seen this before.

I have an older site built in Foundry 1. It was last opened before I purchased Foundry 2. Opening the site now I get the warning that the Foundry control stack is missing. It’s not, it’s there, as per the image below, but it’s now the Foundry 2 control stack, not the Foundry 1 stack. All the styles in this Control stack have reverted to default.

If I remove this stack and replace with a new version (still F2) the red warning goes away but of course, I’ve lost all the style settings.

I’ve tested a few older sites built with Foundry 1 and they all exhibit this issue. Which is concerning!

Anyone else seen this?

EDIT: Just remembered there is a Foundry forum so have posted this there as well.