You can make sure screen recording goes more smoothly if you reduce the amount of possible background active apps in the iOS app switcher.
Reduce the amount of active Website tabs in the Web browser and reduce the amount of notifications your apps get, as well as, the frequency that the mail app fetches mail.
Look in Settings app, under Notifications and for the Mail app,
mail fetching frequency is found in Settings app under the Mail settings panel under accounts.
Your iPad maybe just be running too many behind the scenes/background processes while trying to do screen recording.
You may, also, choose to individually toggle OFF Background App Refresh for certain kinds of apps in the Settings app, under General settings panel.
Best of Luck to You!