Apps with cloud down arrow

The icon that you describe indicates that the App has been offloaded from your iPad - often to release free space when you have limited device storage. Apps will reinstall when accessed - unless the currently available App is no longer compatible with your iPad, or has been withdrawn by the App Developer or Apple.

Try to find the App(s) with which you are having difficulty in the Apple App Store - and attempt to reinstall from there.

Bearing in mind that apps are permanently tied to the Apple ID and password that was used to download/install them on that device, if you see that cloud with arrow down icon close to some apps (going to AppStore, tapping on your symbol at top right corner, then tapping on "app") but you can't re-download/re-install them, it means that someone deleted them from the iPad when a different Apple ID was in use.

Regards

Giulio