MediaInfo, debug log and we can work out what the issue is.
The last logs you posted showing a playback issue used Kodi’s built in SMB client, which has already been advised against when playing 4K or similarly demanding material
This confirms what I said earlier, that libsmb and Kodi’s SMB client won’t provide a great throughput for 4K video because it doesn’t have readahead.
One of the clips you are playing back, Planet Earth 2 in 2160p 4K HEVC, cannot be played back on Pi 3. Kodi’s built in Samba client doesn’t provide enough throughput for this video and for very demanding 4K content, you do need to use fstab based mounts. I believe that’s why we are embarking on this
4K files with high bitrate will struggle with Kodi’s built in Samba client. I’m hopeful this will change in the future with Kodi v18. For now – an fstab based mount is recommended.
Can you see the version ? I won’t be able to reproduce it with previous and last version on the RP3 but you might be able to see it ? If not, may i suggest to focus on the log i already posted/will post tomorrow ?
Sorry if i’m not clear but it’s hard to explain & explain