I am having the same problem on my parents Vizio. Status bar pops up every few seconds then the 3 dots appear in the middle of the screen.
Server (running on Windows 10) was 1.3.4; same problem with 1.4.4; with 1.5.0, the TV never gets past the PLEX screen.
Anyone have 1.3.3 download link for me to try rolling back to? Unfortunately, I deleted the installs from my update folder a few weeks ago.