App not given focus when switched to via keyboard

When switching between apps via the keyboard, an app appears to have focus but does not respond until a mouse click is actuated. The issue of focus is not limited to specific apps, although it's more of a pain with some apps than others. This behaviour is only in macOS26.

Examples:

1. When switching apps via the keyboard to a web broswer (i.e. FF, Brave or Safari) it's not possible to move between open tabs or to the address bar via the keyboard. A mouse click on the web browser is required.
2. When switching to Messages the focus doesn't always default to the text entry area. The user often has to click in the text entry box before typing.

This behaviour has never been present prior to macOS26. This is not expected behaviour and makes it very difficult for power users who primarily use the keyboard (not a mouse or touchpad).