I see this problem FREQUENTLY! This has apparently been an issue for quite some time without any sort of solution. At this point, the Plex App is at version 2.11.1 on the PS4 and PMS is current as well. I’ve noticed this behavior through several iterations of both PMS and PS4 Plex App updates and it always manifests the same way – seemingly random requests from the PS4 to re-register the device via the 4-digit PIN.
Things I’ve Noticed:
It appears to happen whether I choose to shut the PS4 down entirely, or put it into Rest Mode.
The Devices sections on the PMS Web App will ‘collect’ the registrations of all of the previous versions of the PS4 App.
I have two PS4’s. One, activated as primary seems to be affected more than my secondary unit (in fact, I can’t recall if my second PS4 has ever asked me to re-register)
Like the OP, this appears to be random. Sometimes it will ask me every couple of days, sometimes the interval will be wider.
I would be glad to post any information required to get this fixed as it is **the single most annoying issue **with PMS (for me at least). While I appreciate that I can re-register on a mobile phone, I shouldn’t have to.