I'm going to guess that when the users click into the field, it's the actual field. You should use a global field (text) instead; using the Value List which is based on the real field with the unique text values. [ I'm assuming that this choice is happening in a Form view layout, not in a list, as a global would visually change on all records.]
The global's value belongs to each user. It can be cleared by the script, after it's used to tell it what to do, if desired, at the end.
I will work on the Global. That makes perfect sense. I have developed a work around using a static custom value list and not a dynamic one. I appreciate the guidance toward the Global.