It’s as if all the tech weenies decided to turn on strict DNS-Rebinding protection everywhere because they thought we would all be out drinking and wouldn’t notice.
There is a lot here to unpack.
Version 1.21.0-3744 and Synology, that is a pretty old version and I suspect you got hung up during a DSM6 to DSM7 upgrade. You can try your hand at the how to’s or yell for ChuckPA Synology FAQ - Questions, Answers, and a few How-To's
DNS Rebinding - check for these messages in your ‘Plex Media Server.log’
Plex Media Server.1.log:Dec 31, 2022 11:32:16.808 [0x7f46037060d0] ERROR - getaddrinfo(192-168-1-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct) failed: -2
Plex Media Server.1.log:Dec 31, 2022 11:32:16.808 [0x7f46037060d0] DEBUG - Network: 192-168-1-1.abcdefghijklmnopqrstuvwxyz012345.plex.direct failed to resolve to 192.168.1.1 but instead yielded ""
Clients may work locally but browsers won’t. Remote access is another thing to work on after the DNS is sorted. What router do you have?
