I try to add a tag and it flashes "added" but then isn't displayed.

This is a known issue that we'll try to get fixed up soon. To add a tag ensure you hit the "Enter" or "Space" key after the tag and it should be successful. Here's a video explaining it further: https://www.loom.com/share/36d3f10d4b6942c0b76d13deaad05550