Changing the filename and adding the correct keywords gives a correct result (This does not require changing attributes, which are not hidden, not system, archive-ready, not read-only).
However, renaming files directly on the Meta Quest 3 is not supported in the native Files app. The best method is to take off the headset, connect the headset to a PC via USB-C, put on the headset, allow file access in the headset, take off the headset, rename files directly through the Windows File Explorer, disconnect USB and put on the headset.
AI tells us that alternatively, you can use a third-party file manager app, such as Total Commander or another Android-based file explorer, via Sidequest to manage files directly on the headset. However, you should create your organization as a developer of Meta software and register it before you can install any third-party app via Sidequest.
If you guess is wrong (i.e., the video is 180 OU rather than 360 SBS), then you need to repeat this procedure.
Every video which has no keywords in its filename needs the same procedure. It is very inconvenient.