2017 Seat Leon 2.0 TDI FR - Intermittent Engine Management Fault with P047F Codes

Hi, I've been experiencing an intermittent engine management fault on my 2017 Seat Leon 2.0 TDI FR. The check engine light first appeared about three months ago. After scanning the vehicle, I found two identical fault codes: P047F $07E8 and P047F $07E8PD. My mechanic initially recommended replacing the two emissions control valves located at the rear of the engine near the top — a relatively simple and affordable fix. However, this did not resolve the issue. He then suggested replacing the exhaust pressure control valve within the exhaust system. This action temporarily cleared the fault for about four days before it returned. To gain better insight into the problem, I purchased an OBD2 scanner to clear the codes myself, which works well — but the fault reappears either the same day or the next day during driving. Given that the issue is intermittent and persists despite these repairs, could this be due to a different component or a faulty sensor? Any advice or insights would be greatly appreciated.