Steps to reproduce:
- visit Special:Homepage with a user with no prior task type settings on a wiki where none of the default task types exist, e.g. https://pa.wikipedia.org/wiki/%E0%A8%96%E0%A8%BC%E0%A8%BE%E0%A8%B8:Homepage`
- go through onboarding if needed, and reload the page
You'll end up with an empty task filter list but lots of tasks in your feed.
Similar error happens if a user does have prior task type settings but those task types don't exist anymore.
What's happening is that the API interprets an empty list of task types as "give me all types" (it's a convenience so people don't need to manually enter each). Normally the UI prevents you from deselecting all task types, so this can't happen, but when the default types don't exist, the filter starts with all types unselected.