Web player shows update required, have to dpkg -i manually

Server Version#: 1.15.3.876

Since installing PMS a few versions ago, when I log in to the web client I get a banner telling me when there’s a new version out, and that I need to install it manually (same in the Settings section). So I download the .deb, upload it to the server an its OK until the next update.

Why isn’t the .deb getting installed automatically from the repo though?

This is my /etc/apt/sources.list.d/plexmediaserver.list file:

deb https://downloads.plex.tv/repo/deb public main

When I run apt update I get:

Hit:1 http://gb.archive.ubuntu.com/ubuntu bionic InRelease
Get:2 http://gb.archive.ubuntu.com/ubuntu bionic-updates InRelease [88.7 kB]           
Get:3 http://gb.archive.ubuntu.com/ubuntu bionic-backports InRelease [74.6 kB]                                                                     
Get:4 http://security.ubuntu.com/ubuntu bionic-security InRelease [88.7 kB]                                                      
Hit:5 https://downloads.plex.tv/repo/deb public InRelease                                                     
Fetched 252 kB in 3s (98.5 kB/s)                                                                              
Reading package lists... Done
Building dependency tree       
Reading state information... Done
All packages are up-to-date.
W: Conflicting distribution: https://downloads.plex.tv/repo/deb public InRelease (expected public but got )

What’s up with that warning? Is this the reason why I’m not getting updates? This was the subject of this thread, but that was closed back in February.

Anyone give me any clues? Thanks.