[Mort]

I’m paying a subscription but on chrome I only get occasional 1080p I on a 1gbp internet connection so why does it do this?

I think Disney+ is like the other streaming services, where bit rates you can stream on PC are limited due to limited Widevine support in-browser. Unless the services offer content at L3, 1080p and higher typically requires Widevine L1 and/or PlayReady 3.0 (which will only work if you use the UWP apps from the MS store and a supported CPU), whereas I believe all current browsers still only support up to L3 in software. The UWP apps for things like Netflix and Disney+ should let you watch higher quality levels where the streaming service allows it.