Audio Lag Issue that isn’t present in other players

Hi, i’ve read the rules and hopefully i’m meeting at least a few of the posting criteria!

I’m running Jarvis on a Windows 10 machine, 1080 card, 8 gigs of ram, i7 processor etc. I have no horrific repo’s installed or anything weird, I am just wanting to use Kodi as I have for years for my media library of movies and TV shows.

Until recently everything has been fine, I run an HDMI cable taking audio and video to my Onkyo amp which then does the leg work and makes everything sound and look awesome. Recently however, some video’s have had really bad audio lag right from the beginning, that seems to get worse as video’s progress, it’s not everything I watch but it is numerous enough for it to be a problem. Sometimes it is marginally out and stays that way, and sometimes it gets worse as I have said previously. Jumping around the video sometimes appears to fix it for a short term but I can’t be certain if i’m over analysing it!

I have tried the same files in Plex, VLC and MPC and not had any problems at all with lag and audio has been output correctly. I really don’t want to have to ditch Kodi because I just prefer it to Plex so much so, I was hoping there might be a fix or some suggestions for me.

If I can post anything to assist you further, I would be happy to do so, but any guidance would be greatly appreciated, many thanks!