PI (filter) Changing projectsettings

I have a resolve timeline 1080. when I go in PI it also says 1080 in the viewer. After applying to resolve it makes a 4k. I go back to PI wanting to change the project settings (see attached) but I am not able to change these - any idea what I’m doing wrong? The custom settings are 1080, but the pop up when tabbing frames under the view is 4k.

Is the source layer in Resolve 4K? PI will get the size from the layer I believe

Alan.

Thx for your quick reply and sorry for my late one,
When I look everything through I can’t see why, I think this is one of those where I just start over and make it nice and tidy from the beginning - I’m just eager trying to understand everything, I’m sure it’s a user mistake.