I’ve been a Plex pass user for quite a while - in fact several years - but again and again I notice that the support for common problems is extremely poor. Since mid 2015 people report the PS4-Version of Plex to be more or less the ONLY Playstation-Application that does not work at all with Logitech Harmony Remotes. This is despite the fact, that Logitech has done a quite good job - as the remotes work fine with everything else I use on the PS4.
IMHO the problem is that the Plex App does ignore “keystrokes” from other devices that the native controllers and should be very easy to fix.
A quite similar situation has existed or still exists on FireTV: the App crashes on startup and requires the data to be reset or the device to be rebooted to get Plex working again. Also reported since the beginning of 2015 an AFAIK up to today no fix.
Plex as a company should consider the problems of their customers as foremost priorities. Both these are not nice to haves but essential functionalities. If they are not provided, people will start turning their backs to the products and somewhen Plex will be gone - “nobody nowing why”… This would be very sad indeed, as the poduct itself is very good.