with krypton, pulldown correction (pc:1) in codec info (keyboard o) is active even if frame rate switching is on. on jarvis codec info shows (pc:0). if frame rate switching is on. i think this is because kodi drops the "old" am-codec support. since v17 they only use Android Media Codec.
this is from the kodi forum by a AMLogic Dev.
"Something maybe I can add, as an internal developer inside Amlogic. XBMC/Kodi runs on Amlogic's chipset in two modes: either through amcodec acceleration, i.e. am-264/265, etc, or through the Android standard MediaCodec API (amc-XXX). If amcodec acceleration is being used, then the video playback is fully controlled in its own pipeline and Android/system does not have any effect over the frame rate conversion. The newer Amlogic's Android release has HDMI refresh rate matching, so 23.97fps source will make HDMI output goes to 23.97hz or 59.97hz accordingly. However, if MediaCodec is used (when the acceleration is off), then the rendering of video frames are all controlled by XBMC/Kodi's logic. When and how the frame rate conversion is made is all controlled by application and normally there is no way for the application to do any HDMI output mode matching without other special hacks on a rooted system."
i don't know how libreelec will handle this stuff, but with v17 (any version) i never got (pc:0)