Problems with Safari in Apple OSX 10.13.4 Beta

After upgrading to Apple OSX 10.13.4 Beta on my Client computer, Plex Web no longer works properly. After playing a video for only 15 seconds or so, it appears to stop streaming, then starts streaming again at a later stage of the recording. Very weird behavior. Not a problem if I use other browsers on the Client. Also a problem if I upgrade the Server Computer to 10.13.4 Beta. Everything works fine except the Web version of Plex when run in the Safari browser. All other Client software (Plex Media Player, Plex for iOS) working fine.
The solution is to either reinstall the older OSX or use another browser (the much easier solution!).

Has anyone else noticed this problem?

This problem still exists in 10.13.4 Beta (17E150g) release. I’ve reported it to Apple. Has anyone else encountered this problem?