Hi!
First, make sure that you have your Download ID configured in both of the components. Go to https://www.akeebabackup.com/my-subscriptions.html and find your download ID below the list of subscriptions. It's a 32-digit alphanumeric string. Copy it. Now go to Akeeba Backup, Component Parameters and Admin Tools, Parameters (the tolbar button on the top right) and paste the Download ID to the same-named field in both of them. Then click on the "Update found" button, click on "Refresh update information" and you should be able to update.
If this doesn't work, manual update works just fine. Just download the installation ZIP archives of both components from https://www.AkeebaBackup.com/latest and install them through Extensions, Install/Uninstall without uninstalling your existing versions. When installing a newer release of our components on top of an older release, an update is automatically performed by Joomla!.
Nicholas K. Dionysopoulos
Lead Developer and Director
🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!