Sounds a lot like a netwok issue maybe your connection cant handle the stream or its on slow server.
I would agree it sounds like a network issue & that's was what I initially thought, However if I play one of the apps I often have the sound issue with within Kodi (using RPI2) on my laptop, phone or tablet but just by using the app (i.e. not within Kodi) then I do not have these sound issues. As when playing the app on these other devices is using the same network (but no using LibreElec / Kodi) that made it appear as more of a Kodi problem as opposed to network.
I am not really too familiar with debug files