As you can see in the video (link) the temperature is all over the place. It jumps up randomly and then slowly goes back down then starts the process all over again. Not sure if this is a sign that something is wrong however the system is stable. Maybe I'm just worrying over something that is completely normal?
This is how XFR2 works, the CPU frequency will constantly jump around, going up higher when needed and backing off at idle. Even while it is backed off, it tends to jump around due to windows tasks and what not and this is where the jumps come from. I see the very same behavior on my 2700x so do not worry!