Do you see RADIUS Live Logs? If so, then you can enable the ISE Messaging Service again, and if Live Logs are still fine, then that's not an issue. If you get Queue Link Errors, then you should create a CSR for the ISE Internal CA Cert - that will sort out the Queue Link Errors.
The Context Visibility Reset Procedure is documented here and it's a very precise and intricate sequence that must happen on Primary and Secondary nodes. I hope you followed the exact procedure?
If that still doesn't populate the Context Visibility, then you might need to speak to TAC.
Did this ever work?
What do you see on the PAN/MNT nodes when you run
show application status ise
