I have the same issue, and the same resolution worked for me as well Though i should note that closing the plex web page doesnt resolve the problem, hitting F5 does, or fully closing chrome, sometimes a freshly launched chrome will have the issue as well which leads me to believe this is an issue with cached data or the web server(i do not allow chrome to run in the background).
EDIT: completely restarting the machine does not seem to resolve the issue either, at least not today, when i notice the problem i normally cant restart the server because it is recording.
On both of my Windows 10 plex DVR servers. One 1809 build 17134.523, one insider preview build 18309.1000, server running 1809 is on plex server version 1.14.1.5488(standard update channel) server running insider preview is running 1.14.1.5488(beta update channel) they are the same build number.
Both servers are set to grab the enhanced guide but the insider preview/beta update server doesnt do much recordings. its just an early warning system for updates that may kill plex, plex DVR, or my IP cam NVR(iSpy) this early alert server came in handy during transition from 1511 to 1607 and a few other incremental updates. Both servers have the issue, and both are resolved by hitting F5 on the client computer.
The problem so far only appears on browser(chrome only though i may switch to firefox/IE/EDGE to see if it is present there.
The problem has not been observed on android app or windows app. i dont use the android version often to search for upcoming movies, and i cant remember the last time i used the windows store app, just downloaded the windows app, there is no option to view live content or the upcoming schedule that i can find.
I should note that i have had this issue in the past for upcoming TV shows but for the past several months it has only been an issue for upcoming moves and is far less common though i may just be searching less often.
Strange thing about the windows app vs web page, the audio of a just installed plex app is much louder than chrome web page, i dont think i will need to turn down the audio to 50% on all my games any more also somehow the windows app uses marginally less CPU(within margin of error but consistently lower), and noticeably less GPU 15% vs 9% on a GTX1080 on 4K display, though this is probably overhead from chrome