2013 VW Passat TDI P204F Fault Causes ADBlue Error - Can Def Code Be Reset?

Hello, I recently encountered a persistent ADBlue error on my 2013 Volkswagen Passat TDI with a 2.0-liter diesel engine. The vehicle is now displaying multiple fault codes: P0475, P047F, P204F, and P023A. While I understand that P0475 relates to the flapper valve — which shouldn't directly impact ADBlue functionality — the root cause appears to stem from the P204F fault, which is triggering downstream issues. My main concern: I've successfully cleared these fault codes using a diagnostic tool, but the ADBlue warning light (showing a DEF can and wrench icon) remains active. After driving approximately 80 km without any restarts, the dashboard still indicates only 20 km of remaining DEF life before the engine will not start again. This behavior is alarming — is this normal? Shouldn't clearing the codes reset the ADBlue warning and restore full functionality? Additionally, has anyone else experienced a P204F fault on their 2013 VW Passat TDI? What are common troubleshooting steps or components to inspect before attempting further repairs? I'm looking for reliable advice from owners with similar experiences. Thank you in advance for your insights!