Desreferencia de una posible referencia NULL?

I. Hola Alfredo, en mi caso no conozco la respuesta pero he visto parte de su consulta/este conflicto tratada por expertos aquí en foros en Inglés y deseaba dejarle una parte de ellas por si pudiesen serle de utilidad mientras le atiende un experto. Disculpe la cantidad de lectura y todas las molestias, mucho ánimo.

https://es.stackoverflow.com/questions/75999/qu%C3%A9-es-una-nullreferenceexception-y-c%C3%B3mo-solucionarla 

https://es.stackoverflow.com/questions/615192/por-qu%C3%A9-me-da-error-cs8602-y-no-me-permite-mostrar-la-informaci%C3%B3n-en-messagebox 

https://stackoverflow-com.translate.goog/questions/75394307/dereference-of-a-possible-null-reference-c-sharp?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc 

https://stackoverflow-com.translate.goog/questions/59524568/why-do-we-get-possible-dereference-null-reference-warning-when-null-reference-d?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc 

https://stackoverflow.com/questions/70894115/dereference-of-a-possibly-null-reference-can-my-code-be-simplified 

https://es.stackoverflow.com/questions/571754/c%C3%B3mo-evitar-correctamente-nulls-en-propiedades-de-objetos

https://stackoverflow.com/questions/75394307/dereference-of-a-possible-null-reference-c-sharp 

https://www-slideshare-net.translate.goog/slideshow/non-nullable-reference-types-in-c8/133829790?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc&_x_tr_hist=true 

https://www-codeproject-com.translate.goog/Messages/5943188/Net-Core-6-IMongoCollection-Suppression-State-Warn?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc 

https://www-christianfindlay-com.translate.goog/blog/stop-nullreferenceexceptions?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc

https://learn-microsoft-com.translate.goog/en-us/dotnet/csharp/language-reference/compiler-messages/nullable-warnings?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc 

https://stackoverflow.com/questions/72482732/how-to-resolve-a-cs8602dereference-of-a-possibly-null-reference-when-redirecti 

https://www-syncfusion-com.translate.goog/blogs/post/whats-with-c-8-0-nullable-reference-type?_x_tr_sl=en&_x_tr_tl=es&_x_tr_hl=es&_x_tr_pto=sc 

https://www.reddit.com/r/csharp/comments/q8rtd5/confusion_on_dereference_of_a_possibly_null/