QoS2 messages are not deleted when the limit is reached

Question

I’m interested in a situation where mqtt client doesn’t send PUBREL for some messages and after that my queue (maximum number of pending PUBREL) is full. After this my client reconnects and is unable to send messages because my queue (maximum number of pending PUBREL) is full. My client has a session_expiry_interval property because it is important for the client to receive messages. After reconnecting, my client is not aware of the previous messages. I’m looking for a way to allow my client to send messages after reconnecting. As I understand it, this requires that the maximum number of waiting PUBRELs stops being full. Could you please advise if I’m doing everything correctly and if there are any other client parameters that need to be configured?

Now I have Max Awaiting PUBREL Timeout = 300s, clean_session = False.