Fatal error: during premium theme upgrade

Fatal error: Uncaught Error: Call to a member function get() on boolean in /public_html/wp-content/plugins/jetpack/sync/class.jetpack-sync-module-themes.php:171

WordPress: 4.8
Jetpack: v5.0
Theme: Divi

This update was not run through sync, but completely independently of jetpack or anything to do with it.

Why is JetPack sync plugging into plugin updates when they’re not being run through jetpack sync?

If you’re going to continue to do this, please take care and run appropriate object instantiation checks before accessing them.

Many thanks.