@jkhkhbjhbj In the Cordova context we got the Cookies to move in both IOS 18.0 and IOS 18.1. IOS 18.0 being more complex. We basically had to manually inject the cookies from the NS to the WK store. This worked in 18.1 but in 18.0 we have had to one more step to launch the InAppBrowser plugin with a dummy URL to the server (Hidden Call). This then made the cookies available in the IFrame as well.
!Important :
You could also be hitting issues with the Cookie SameSite where when not passed from server will default to Lax not None like it did before. This can cause issues in an iframe as well as it does not send Lax on post requests. We fixed this by making sure None was set from the server side ( can't do this locally).