Already posted this in TVMosaic forum (support ticket is also still open) and Kodi forum ( https://forum.kodi.tv/showthread.php?tid=331546&pid=2737053#pid2737053 ):
After client wakes up my TVMosaic-server (Win10), first attempt to playback a tv channel doesnt work.
After rebooting my client (and server is "online") everything works fine.
If i take a short look in my kodi log, it seems that this is maybe timeshift related (no such issues when "timeshifting" is disabled in TVMosaic PVR Addon).
http://ix.io/1cAr