After the HP Support Assistant installed HP Display Control UWP (SoftPaq number sp112943, Version: 4.6.44.0) on April 1 my external monitor connected via via USB3/Thunderbolt began to flicker (brightness would dim and brighten about once every second). I first suspected this was due to a bios update to F.28 installed via Windows Update on the same day, but the issue was fixed after I uninstalled the HP Display Control UWP. Just an FYI in case others are having similar issues.
I continue to have buggy charging through the Thunderbolt ports (see my other posts).
I have a Spectre x360 - 13-aw0023dx with an external Samsung [personal info removed] monitor.