Same problem.
Kodi 18.6 (Image OpenEight-6.7-sf8008-20200317) --> the same problem: Ac3/DTS - KODI - nur stereo Kodi 17.6 works AC3\DTS OK.
Thanks ;)
Thanks for solving the problem;)
More streams (720p, 1080p, 4K) in Stream Cinema plugin (online) In PC is all OK.
I join the quest for the smooth playback in the KODI. Thanks