Raising the TA with baking soda will only make the pH climb faster. If anything, you might need to lower the TA.
Even at a TA of 50 ppm, the pH can still climb from the outgassing of carbon dioxide. If the water is heated and/or aerated, the outgassing will be increased.
If the pool has a salt water chlorine generator, then the pH can rise from that. If the pool uses sodium hypochlorite, then the pH can climb if the sodium hypochlorite has excess sodium hydroxide. If the pool has been plastered in the last 30 days, then that could contribute to pH rise. If the plaster is over 30 days, then a low CSI can contribute to pH rise. If the pool has scale and a low CSI, then that can contribute to pH rise.
Increasing the pH to 7.8 can help reduce the amount of carbon dioxide. Increasing the Cyanuric Acid level will provide some pH buffering and will allow you to use less cell time and/or sodium hypochlorite.
Adding borates to 50 ppm will help buffer the ph from rising as fast.
Also, if the TA is not rising as the pH does, then the pH rise is due to the outgassing of carbon dioxide. If the TA is rising as the pH does, then the pH rise is due to the introduction of some sort of base. What is the target pH, how fast does it rise and what is the TA doing?
What further details can you tell us about the pool? Indoor/Outdoor, all chemical levels, SWG, concrete, vinyl, fiberglass etc?