Sorry to hear about the recent issues you have been experiencing.
Please read these articles for setting up External MIDI Devices with Studio One 3:
Also, make sure the keyboard is set to external MIDI clock.
1. For the piano keys of your Casio, you will need to create a New Keyboard, with the MIDI Receive From assigned to the MIDI port the device is connected to, but don't need the MIDI "Send To." Set this to Default Instrument Input.
2. To use the Sounds of the Casio, you will need to create a New Instrument with the MIDI "Send To" set to your keyboard MIDI port. Check all the MIDI clock options.
3. Also, to monitor the sounds from the Casio, you will need to connect audio cables from your Casio to the audio interface of your computer.
Then check out this article on setting up to record using an External Device: Setting up to record with an External MIDI Device Studio One:
In regards to your question about replies, please create a support ticket if you would like to discuss an issue in more detail.
We also encourage you to create a thread about this on the Presonus user forum. https://forums.presonus.com/viewforum.php?f=108 This will allow for back and forth discussions about an issue or question and more points of view as to possible different approaches or workflows.