Hello there iandwk,
We understand apps aren't fitting the screen when you open them occasionally and appear too large on your iPad. We're glad you've joined us in Apple Support Communities, and we'd like to learn more to see how we can help.
To begin, you'll want to be sure your iPad is updated to iPadOS 15.2.1, and check to be sure all your apps are updated. You can check the current version installed by visiting Settings > General > About. If needed, learn how to update your iPad and your apps from the links below:
Update your iPhone, iPad, or iPod touch
How to manually update apps on your Apple device
Next, if you've ensured your iPad and all your apps are updated and the issue persists, let us know which specific apps you're seeing this behavior with. Also, try the steps in this support article:
If an app on your iPhone or iPad stops responding, closes unexpectedly, or won’t open
Send over these details, and we'll take a closer look from there.
Cheers!