Video 6 seconds ahead of Audio

this is getting epidemic on plex, but plex blames xbox live, who blames my internet provider, who blames my mother. Plex is getting user unfriendly fast with me over this very quickly, can I get an honest answer to the problem, oh, and these ( about 110 out of 938) movies were fine last month, and I’ve made no changes. Why would any audio ever be out of synch with the video? they are coded together are they not?

now half the movies I try. even ones watched before that there were no issues?
are there other plex users that this is an issue?