Confirmed this is a libinput regression - I've built and installed libinput 1.8.4 from Artful and that returned the RMB click functionality (though of course many other things that rely on libinput >= 1.9 broke).
** Package changed: xinput (Ubuntu) => libinput (Ubuntu) -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to libinput in Ubuntu. https://bugs.launchpad.net/bugs/1777395 Title: [bionic] Dell precision touchpad RMB no longer works To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libinput/+bug/1777395/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp