Hi Ryan
I use XE 5.5, the latest build, and have found similar problems in both trying to cutomize hypertext in list boxes and in regular text. The work-a-round I've used successfully with list box hypetext is to designate a totally new customized item, like text10, which then seems to hold up.
Hypertext instability was an issue in earlier builds with a remedy in 5.14. However, in a project I've been working on, now using 5.5, customized hypertext is temperamental, and shifts to another font and color when simply navigating in the editor from one page to the next and back. This was sufficiently an issue that I removed all hypertext and used hotspots instead (a viable work-a-round, as well). I've sent a sample to DW a few weeks ago for them to reproduce the issue.
So, if you continue to experience an issue with the customized hypertext, try establishing a new one with new name, or use hotspots.
Kind Regards,
Stephen