when systemtray of teamspeak3 is enabled. plasmashell will start using more CPU with no reason. this is only happened on Intel Graphic Card. My Nvidia Graphic Card did not has the problem Ubuntu 16.04.2 kde 5.9.4 teamspeak 3 3.1.3 with its own QT library.
updated information this is also happened on nvidia card. same phenomenon.
Can you check whether there's DBus spamming going on by checking dbus-monitor. I have the feeling that Teamspeak constantly signals updates to its context menu.
thanks for giving my information. it actually teamspeak3 continuous span the dbus. I may report to teamspeak3 author