Hi,
[gallery] is the BBCode of the XenForo Media Gallery...
You changed the [gallery1] from VW to [galleryw], which is used for images. Ok, i don't use it in an article.
All prefixes set as new by me have the usage example [gallery]? WHY ?
Prefix File has [file], ok
Prefix Help has after creation [gallery] ???
Prefix XXX has after creation [gallery] ???
I don't think it is working as designed, and: it has already worked once when I created the article.
I'm a little bit confused....