You can disable the Automatic Before Update in the “Settings” tab > click “Show Expert Settings” > deselect “UpdraftPlus Automatic Backups:” and make sure to click on the “Save Changes” button after.
Can you please confirm that you are using the latest version of UpdraftPlus?
Could you also try to reset/wipeout UpdraftPlus settings in the “Advance Tools” tab? Please note that by doing this, you will have to re-setup all backup schedules, remote storage and other settings again.
Thank you for your video but the popup is showing in the Plugins page not Updates page. If you update plugins in Plugins page it will keep popping out each time.