Adding multiple tags separated by commas in support forum only produces the first tag and cannot be updated for more

[webdevmattcrom]

Steps to replicate:

1. Create a forum thread (I did mine here: ​https://wordpress.org/support/topic/using-blubrry-as-prefix-breaks-my-audio-files/#post-18064971)
2. Add multiple tags to your post/reply separated by commas. I attempted: blubrry, analytics
3. Note that only the first tag is created, not the second
4. Try to use the Edit feature and update the reply with multiple tags, and see the same result