Mobile animation is disabled by default to improve user experience on mobile devices.
Mobile animation does not work for multiple reasons, in particular:
You can enable mobile animation in Zero Block: in the desktop version of the Block Editor, select an element → open Element settings → add an animation effect (for example, a step in Step-by-step animation) → switch to the mobile version in Zero Block → click "Switch on" under Mobile animation in the Element settings panel → Save the changes. Now the element animation is active on mobile devices.
Learn more about animation in Zero Block: