When installing pxc from apt in ubuntu 16.04 through “wget https://repo.percona.com/apt/percona-release_0.1-4.$(lsb_release -sc)_all.deb” after purging the latest pxc version one can install is 5.6. If you wish install 5.7 you NEED dpkg -i percona-* AGAIN. Perhaps some issueses with uninstall scripts. Hope this info will be helpfull in case someone stumbles upon reinstallation from scratch.