This is on both IOS and Android versions. I know it was 'fixed' in 2017 but has reccured.

Started in the latest version (1.14.0 / 1.14.1), mob spawners no longer have the mob spinning around inside spawner. Was there in earlier versions but has suddenly gone in one of the updates. I do not have any texture packs on that effect spawners. The spawner still spawners mobs but the spawner cannot be identified without it spawning mobs or in peaceful mode.