Learn how to hide suggested and recent applications from your iPad Dock to keep it tidy and prevent the Dock from changing its size or displaying apps you don’t want there.

The Dock on your iPad is just as handy as the one on your Mac. You can place your most frequently used apps in that spot for quick and easy access at all times.
Another great feature is having your recently used apps in your Dock. However, for some, this can be too cluttered and may not always be convenient. For instance, just because you opened your Settings app to make a quick change doesn’t mean you’ll open it again soon. For these reasons, you can turn off the feature.
Disabling Siri suggested or recent apps can also help if you find that the frequently changing Dock messes with your muscle memory.
Hide suggested and recently opened apps from the iPad Dock
Open the Settings app on your iPad running the latest version of iPadOS and tap Home Screen & App Library. Then, turn off the switch for ‘Show Suggested and Recent Apps in Dock.’
If your iPad is running an older version of iPadOS, go to Settings > Home Screen & Multitasking and turn off the toggle for Show Suggested and Recent Apps.
You’ll see the change to your iPad Dock immediately. Only the apps that you parked in your Dock will display from now on.
Whether you use your iPad for work, play, or a little of both, setting it up so that it works best for you is important. This setting can help declutter your Dock and let you truly access only the apps you want from the Dock.
For more, check out: How to customize your iPad Dock