It took so much time because earosacoustic.com uses a very early Magento 2 version (it is partly 2.0.2, partly 2.0.7).
The early Magento 2 versions contain a lot of issues, including compatibility ones.
If you will encounter similar problems with other extensions, then consider to upgrade the website to the latest version (currently it is 2.2.1).
I provide my Magento 2 upgrading service for it.