Brave on Android does not play Opus audio files on a site using jPlayer¹. It plays Vorbis (where that is used) on the same site. Chrome on the same device plays both formats.
Here is one Opus file, which Brave does not play: https://www.andromeda.se/sommarljus/index.html
I use Brave 1.0.49 on Android 7.1.1 on a Moto G4 Play. Scripts are allowed.
The same version of Brave on a Samsung Note 8 with Android 8.0.0 plays Opus on that site.