Wrong fps in Youtube App

Hi there,
if I use Youtube with a Video Setting of 1.440x60fps, videos are getting a wrong fps-set. They stutter, as if fps would be set to 30 or 40. Setting the videos to 1.080x60 solves the problem, and due to the “small” screen (compared to a tv) without any loss of details, but i have to set this manually, because Youtube always tries higher settings if connection is stable.
Resetting Youtube is no option, i can only switch to lower settings, which would start videos with 480x60, which is a real loss in details.

Anyone else with this problem?
Not a big deal, but a bit nerving.