I'm not 100% certain if this is a problem with 4.0.0, or a problem with our site specifically. 

'URL' resources historically didn't open 'inside' of the Moodle Mobile app, they would be sent to the browser ("Access the URL" button). Now that URLs open inside the app in 4.0.0 (Android), we noticed that on Android phones in particular it doesn't utilize the whole screen in Portrait orientation. in Landscape orientation, it displays well, using the majority of the screen space. This isn't a problem on an iPhone - both portrait and landscape display the material well, although the iOS device doesn't yet have 4.0.0 available. 

Test Devices: 
Android - Galaxy S22 Ultra, Android 12, Moodle Mobile 4.0.0
iOS - iPhone 13 Pro, iOS 15.4.1, Moodle Mobile 3.9.5 (Latest at time of submission for iOS)

Please see the attached screenshots between the two devices - notice Android-Portrait has about 60% of the bottom of the screen is white space not displaying the HTML content. 

The white space is better seen in the video demonstration, where I am actively scrolling the HTML content, to see where it falls off. 

To reproduce:

• Add a URL activity in a course pointing at a web server serving a secure .html webpage with an 'embed' appearance setting. 
• Access this URL activity through Moodle Mobile 4.0.0 on an Android device in both Portrait and landscape orientations.