using a Sony Xperia X, running Android 8.0
Spotify version currently 8.7.8.233
Ad-silence version 0.5.2

Ad-silence has notification access and is enabled to mute ads. Spotify is enabled under 'select apps', and the Ad-silence notification is always visible on the notification drawer, regardless of Spotify status. battery optimisation is disabled for Ad-silence.

when ads are playing, the Ad-silence notification displays 'listening for ads', same as when music plays, or when Spotify itself is closed.

i also use Spotify Lite, but ads are muted every time (except for the final second), though.

let me know if i can provide any more information. thank you for your time.