My Pi 3B+ supports both 480p/59.94Hz and 480p/60Hz modes (for some reason!). If I whitelist both modes and then play a 480i/59.94 video, then check what output mode Kodi thinks it is using, it reports 59.94Hz; but the actual output (as reported by my display) is 60Hz. If I switch modes to what Kodi thinks is 480p/60Hz, then the output is actually 59.94Hz. It’s as if those two modes have had their labels switched.
Some logs: https://paste.osmc.tv/ivabayupic