Kodi 17.1 playback issues/stalls via SMB

Hi all. I’m a relative novice with Kodi’s advanced functions. I have having issues playing back video files on Kodi (on a new Amazon Fire Stick with Alexa remote) from my networked laptop via SMB. Specifically, I am trying to play a large video file in x264 format (720p). Running Kodi 17.1 on the AFTV. The video plays fine for about 20 minutes or so and then stalls for a few seconds, with Kodi kicking out of the movie and back to the file list in SMB. When I go to resume the video, it resumes fine but will stall out again in about 20 minutes or so. This problem started happening a few weeks ago (also on the older Jarvis version). Prior to a few weeks ago, I have played numerous files from my laptop to completion just fine. This only appears to happen only when playing files from SMB.

FYI, I changed my advancedsettings to: cachmembebuffersize 157286400 (also tried smaller cache sizes down to 30MB or so given the Fire Stick), buffer mode 1, and readbufferfactor 5 (also tried 10). It happens with either settings.

Here is a copy of the Kodi log:

https://pastebin.com/7ENGqcYX

any help would be greatly appreciated!!