Message Search Not Indexing One (1) Room

When trying to index & cache messages in encrypted rooms to be searchable, out of the 51 it finds, it only indexes 50/51, leaving my DMs w/ just one (1) person (on matrix.org & w/ the same settings as many other DMs) unfortunately unindexed. However, weirdly, when performing the caching process w/ `element-desktop` fork `schildichat-desktop`, that client can cache 51/51, where the former fails. I do believe that a similar issue may have been raised here before: #32168

EDIT: even after using the client's _Clear cache and reload_ option (may or may not be related to message caching functions), the _Message search_ window still says:

Indexed rooms: 0 out of 51
Rooms awaiting indexing: 50

Notice, it seems to think the one (1) it keeps missing is done right away? Again, I know what room it is & it's not searchable at all, though.

### Steps to reproduce

1. Security & Privacy
2. Message search
3. Manage

### Outcome

#### What did you expect?
For the room to be indexed.

#### What happened instead?
It remains unindexed.

### Operating system

Ubuntu 22.04.5 LTS

### Application version

Element version: 1.12.20 Crypto version: Rust SDK 0.16.0 (65b585f), Vodozemac 0.9.0

### How did you install the app?

https://packages.element.io/debian/

### Homeserver

chat.prometheus.systems

### Will you send logs?

Yes