Received unknown response E for SSLRequest (expecting S or N)

Could this happen during negatiation?
Using Npgsql 10.0.2, the connectionstring has no ssl settings, so using the default, which is Prefer (I think)
PostgreSQL server is 18.3

<img width="1124" height="211" alt="Image" src="https://github.com/user-attachments/assets/f5ab7c50-0b82-4a88-9738-7f11ea53e938" />
