[BUG] Tagged Radarr items not showing in Plex...(EDIT: 'no release date available')

### Description

My apologies if there are other tickets that refer to this. I looked around and didn't see anything that really matched.

I have a tag in Radarr for items I am waiting for release. There are 127 of them, of which TMDB has metadata on 120(+).

I discovered that using the "Upcoming" feature in the Movies library confuses other platforms I use, such as Postarr. So my workaround was to create a new library (still flagged as movies) and have Agregarr populate the upcoming movies into it.

Things were working ok until I noticed today that most of the items there were flagged in Plex as missing. Sure enough, the folders were gone, leaving only five items.

Looking in the collection in Agregarr and previewing the Radarr pull shows the 127 items. But only the five that are in Plex are highlighted in orange. All the others are highlighted in grey and have the 'add to Radarr/Seeer' buttons on them, which makes no sense as they are already in Radarr/Seeer?!

Searching around, the explanation is that Plex just doesn't know about the movies as yet, so there's nothing to match. But they were matched before?

I had a thought that would solve the issue: use the TMDB metadata instead. Just have Agregarr push the data into place. The separate library could either be set as 'personal videos' and the Radarr/Sonarr metadata stored with each entry. Or the library could be flagged as movies in Plex and matched against the TMDB instead, using local metadata and posters instead of the Plex movie database.

Either way, Radarr/Sonarr HAS the metadata and the posters already. Why not just use that data?

### Version

2.4.2

### Steps to Reproduce

Simply creating a collection on Radarr against a library really. I don't think I did anything special other than creating a separate library for the 'coming soon' items to live in by themselves.

### List Links

_No response_

### Screenshots

_No response_

### Logs

```shell
I'm totally open to working with you to figure this out. That being said, I didn't see anything off in the logs aside from the scan only returning 2 items when there should have been 127.
```

### Additional Context

_No response_