TX Persei is an RV Tauri variable of the RVa subclass, meaning it maintains a constant mean brightness without a long secondary period seen in the RVb subclasses. Like many RV Tauri stars, the light curve shows some evidence of periodicity, with reasonably regular dips in brightness corresponding to its pulsation period. However its pulsations vary wildly, and if you were to phase only a few thousand days of its light curve with the catalog period of 78 days, it would look chaotic indeed
The RV Tauris are believed to be stars in the very late stages of life, only a few steps removed from the asymptotic giant branch and (eventually) planetary nebulae ejection. They share some things in common with the Type II Cepheid (W Virginis) class and perhaps represent an evolutionary continuum.