Please download and install the Xone:24C hardware driver on your PC
This, I believe, will help you to resolve issues encountered attempting to address a single K3 simultaneously with multiple app on Windows hosts
You can find the driver installer at the following link: https://www.allen-heath.com/content/uploads/2025/10/X24C_v5720.zip
Welcome to reply here to confirm if doing so does resolve your issues.
And, if you have also reached out to support, please let me know the helpdesk ticket number for this enquiry - together with the name you use when contacting support, so we can link the contacts if different names/logins are used. This will help us collate similar experiences, or duplicated reports
thnx, Al