Thanks for your answer. I was afraid that would say sth like this since right next to this tab another one is opened with an description how to overclock and which hardware to get. I love my RPi. I surly gonna keep it. 
About that file: It shouldn't be encoded that way, right?
Also: Is overclocking useful if I plan to watch Netflix on the RPi?
Hi!
After upgrading from an old Librelec I found several videos stuttering on RPi 3 with LibreELEC 8.90.007.
As I read through the articles what I could do I found the advancedsettings.xml and took the suggested values:
<advancedsettings>
<cache>
<buffermode>1</buffermode>
<memorysize>139460608</memorysize>
<readfactor>20</readfactor>
</cache>
</advancedsettings>That helped quite a lot. Still some stuttering left though.
Usually the 4 cpu's comined are somewhat between 250 and 350 percent.
Here is the link to the logfile. Playback starts at line 1913. If needed I could provide the file.
I havent seen anything too suspicious... I'm a noob though when it comes to videos, codecs and stuff. So I really appreciate your help 
That behaviour is interesting since the old kodi could playback those files. I also should mention that xbox one media player wouldnt even show a single picture. Another point for kodi 
Thanks!