As long as you are still maintaining your permanent residence in Arkansas, you can legally use your AR license to work in TX for as long as you want, and, in fact, TX won't issue you a license (since one of the compact rules is that you can only be licensed in one compact state at a time). It may be that the HR person just doesn't understand how this works. I would discuss if further with that person or ask her/him to discuss it with the nursing department of the facility. However, that said, employers can deny you a job for pretty much any reason they please, as long as they're not violating state or Federal employment law. If this place feels strongly it would rather hire someone with a TX license, it can certainly do that.