So, seems I have figured out the issue (at least on my Lenovo T460s) and I think it lies with the Intel chip internal GPU.
If you use display port and HDMI-->Display Port adapter it won't work. The Intel chip doesn't seem to support two DP connections at a time. But you can connect Dp & HDMI-->DVI at the same time (or VGA for that matter) & Internal display. So max is 3 displays but they need to be different techs. I can't confirm this for other laptops without external graphics cards since i don't have any more. -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to libxrandr in Ubuntu. https://bugs.launchpad.net/bugs/1771185 Title: Secondary monitor not connecting in 18.04 LTS To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/libxrandr/+bug/1771185/+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