[Appointments+] Can't Edit Service Providers

Latest version of the plugin breaks the Service Providers tab under Settings.

Multiselect doesn't seem to load properly. Instead Services Provided table disables a running list of all services. Clicking the "Edit" button on a service provider leads to nothing.

I can replicate this every time. Using the latest version of Appointments+ (2.3.1) with WordPress 4.9.6 on PHP 7. I have already done conflict debugging and disabled all plugins and used the 2017 theme. Problem still persisted.