DK2 & runtime 1.8: positional tracking randomly jumps around by up to two meters - any ideas?

I've last tested my DK2 with runtime 1.2 a while ago, and have used it a lot with runtimes prior to that, with rock solid positional tracking. Recently I've decided to try the Unity samples as well as official stuff like Home, Oculus Video, Henry, Lost and other applications new to me, and encountered a strange issue: from time to time, positional tracking instantly jumps to a new position, sometimes leaving the origin up to two meters behind - for example, in the Oculus Video Moon Theater scene, I was moved outside scene bounds to the left of the chair. Usually the distance of the shifts is smaller, around 10-40cm. They never happen smoothly (one frame you have a correct position, next frame you have a completely different one), and the shifts seem to put the origin point to a new place. Depending on the application, this has different consequences - in Henry, Lost, Dreamdeck and Home you never leave the center of the scene for more than a few frames (maybe they reset your position if it drifts away too much), but in Oculus Video you are constantly being put into a new position and left there. The jumps happen with varying frequency, usually around two or three times per minute. Here is a short video recorded from Home window, illustrating the problem:

https://gfycat.com/RelievedSpecificBantamrooster

Checked everything that came to mind, from using the debug tool to check if I have performance issues (doesn't seem to be the case, I've got top of the line GTX GPU and my spec is overall well above recommended; the display enabled by the tool shows huge performance headroom and rock solid FPS) to rerunning tracking and runtime setup a few times. Haven't had any luck searching for similar reports on the net so maybe it's a new issue.

Has anyone encountered this or has an idea on a possible underlying reason?

P.S.: I realize that DK2 isn't officially supported by CV1 applications like Home but DK2 seem to work fine with aforementioned apps for other developers, and Oculus have said that things should continue to work for now (until 2017 at least). Developing with a CV1 is not an option for me yet, unfortunately (Oculus doesn't offer shipping to my country).