The output of a date filter is always UTC. The timezone option to a date filter tells the filter what timezone the input is in. But if the input field looks like "2024-08-23T14:38:10.928Z" then that Z at the end means the string is in UTC so the timezone option is ignored.
Depending on what you want to achieve it may be helpful to remove the Z before calling the date filter. In other use cases you may need to use ruby.