You can upgrade from Trellix FRP 4.x client to 5.x using ePO - On-prem.
To upgrade from an earlier version of Trellix FRP, you must first uninstall the existing version.
When you upgrade the Trellix FRP client, it retains all key and policy information. If you are using a different ePO - On-prem server, the encryption keys and policies must be imported from the existing ePO - On-prem server to the new server and assigned appropriately.
Trellix FRP client deployment forces a restart on the client system. The existing Trellix FRP 4.x.x client is uninstalled and the latest Trellix FRP client is installed when the client restarts. All encrypted files and folders on the client system remain encrypted.