During scheduled tasks, Plex is changing the "addedAT" date to the current day and time of scan

While you wait on others more knowledgeable than I to review two things jump out …

Migrations never seem to finish or at least I don’t see it reported in your log as completing …

Apr 01, 2023 08:52:26.790 [0x700000c53000] INFO - SQLITE3:(nil), 283, recovered 790 frames from WAL file /Users/damienburke/Library/Application Support/Plex Media Server/Plug-in Support/Databases/com.plexapp.plugins.library.db-wal
Apr 01, 2023 08:52:26.822 [0x700000c53000] INFO - Running migrations. (EPG 0)

Apr 01, 2023 08:52:29.313 [0x700000c53000] INFO - Running migrations. (EPG 0)

Apr 01, 2023 08:54:24.947 [0x7000009c4000] WARN - [Req#110/Req#122] SLOW QUERY: It took 210.000000 ms to retrieve 1 items.

Apr 01, 2023 08:52:31.354 [0x700000c53000] WARN - [DatabaseFixups] Held transaction for too long (/data/jenkins/server/1785926601/Library/DatabaseFixups.cpp:360): 0.330000 seconds

Network stuff which may or may not be normal:

Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - Network change for advertiser.
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Network change for browser (polled=0), closing 2 browse sockets.
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Setting up multicast listener on 0.0.0.0:32413
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Browsing on interface 127.0.0.1 on broadcast address 127.255.255.255 (index: 0)
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Browsing on interface 192.168.1.166 on broadcast address 192.168.1.255 (index: 1)
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Network change for browser (polled=1), closing 2 browse sockets.
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Browsing on interface 127.0.0.1 on broadcast address 127.255.255.255 (index: 0)
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Browsing on interface 192.168.1.166 on broadcast address 192.168.1.255 (index: 1)
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Network change for browser (polled=0), closing 1 browse sockets.
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Setting up multicast listener on 0.0.0.0:1901
Apr 01, 2023 09:40:56.270 [0x700001f42000] DEBUG - NetworkService: Browsing on interface 192.168.1.166 on broadcast address 239.255.255.250 (index: 0)
Apr 01, 2023 09:40:56.270 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.373 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.373 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.473 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.473 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.573 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.573 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.673 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.673 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.778 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.778 [0x700001f42000] ERROR - [NSB/SSDP] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.883 [0x700001f42000] INFO - [NSB/SSDP] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.883 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:56.985 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:56.985 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.085 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:57.085 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.185 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:57.185 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.286 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:57.286 [0x700001f42000] ERROR - [NSB] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.386 [0x700001f42000] INFO - [NSB] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:57.386 [0x700001f42000] ERROR - [NSB/SSDP] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.491 [0x700001f42000] INFO - [NSB/SSDP] Abandoning browse socket, it was closed.
Apr 01, 2023 09:40:57.491 [0x700001f42000] ERROR - [NSB/SSDP] Error in browser handle read: 89 (Operation canceled) socket=-1
Apr 01, 2023 09:40:57.594 [0x700001f42000] INFO - [NSB/SSDP] Abandoning browse socket, it was closed.

and also this … Apr 01, 2023 08:52:31.337 [0x700001e3c000] WARN - MyPlex: Invalid connection URL 'xxxx:yyyy'.

I would suggest leaving the server running but idle for a while and see if the migrations finish cleanly. Don’t start any scans etc …