I have the same issue with my vive cosmos. Have been trying to troubleshoot, but cant find a solution. Sent a mail to htc, since have experienced it since their last update. I think i had it just before SU11. I have also just before SU 11 installed Tobii eyetracking, so therefore i thought that could interfere somhow, but have not been able to find the solution. Sometimes my view is 8 feet above(as you describe), and sometimes its on an angel too. Moving around with arrow directions does not get me where I should be in the cockpit, since the sim “thinks” im at the right spot.