Basic items to troubleshoot are as follows:

1. Verify that you have enough available licenses for all the apps. I've had an iPad fail to install apps after one app locked it up because it ran out of licenses.

2. Use the "Retry Failed App installs" option in Apps > Inventory > select apps > 'Retry' button at top > hit both options under that button.

3. Resync licenses. Same place as above just click the 'Resync licenses' button.

4. Check the error message to see if it has a specific error that might help track it down if none of the above works. Go to the app details page and find one with the error and click on error under "Status" column to bring up error message box.

Hope something here helps you out.

After re-reading the question, you are having issues with it disconnecting from Jamf School? As in they start the process of installing apps but hang and disconnect?

Are your profiles for management, certs and wi-fi completing and installing?

Have the devices sat for 30 days after being added via configurator? Did the end user remove the management manually if it hasn't been 30 days?

Sorry about more questions.

Why are the devices installed using Apple Configurator? Why not move to ADE enrollment? It sound like the network might be saturated. I would try to set up a Mac, like the Mac mini, cabled on the school network with caching turned on to make sure apps and updates are served on the local network, and not bottlenecked out of the schools internet connection. Also, consider turing on Jamf Safe Internet and limit high bandwidth usage for school hours

Thanks for all the tips.

I think the issue was insufficient licenses for some apps.

I don't have access to the ipads atm, but I will retry in the next days.