What version of Gospel Library are you using? There was a bug similar to this that was fixed in version 5.1. Tags seem to sort by most recent for me, as long as I have "Most Recent" selected at the top of the list. I tested by selecting some text in a chapter, and tagging it with a tag from further down the list of tags. Then, I went to Notes > Tags and saw that the tag was now at the top of the list.
Samuel Bradshaw • If you desire to serve God, you are called to the work.