Almost always, the recommended and sufficient way to completely uninstall an Acronis Cyber Backup Cloud Agent for Linux is to follow Acronis Cyber Protect Cloud: manual uninstallation and execute (as root):
/usr/lib/Acronis/BackupAndRecovery/uninstall/uninstall -a
If you still experience problems with uninstalling or left-overs of Acronis, please use the official documentation.