I am getting multiple reports of this happening. on iOS mobile app, users cannot filter by neither custom fields nor system fields. I am able to reproduce this on my iPhone (iOS version 26.3) with both board view and list view.
I do not have the same issue with the web browser or desktop app. I have also heard from other android users that they did not experience the same issue.
Hello @Chuya. Thanks for reaching out and sharing this feedback. This might be a bug, so to make sure it gets looked into properly, please follow the steps in this guide to contact our support team directly: How to contact our Support Team
They’ll be able to take a closer look and help you out. Thanks again, and enjoy your Asana experience!