Sometimes the DPS dispach in Houston comes up as Statewide Common Base B under the DPS heading.
It's the same frequency & NAC code. The scanner will show it as whichever one it "hits" when a transmission is active.
If you look at the DPS
page in the database, you'll see that "DPS Base B", 155.4675/ NAC 118, is listed for not only Houston, but also Sulphur Springs, Lufkin, Corpus Christi, and Del Rio, among others.