1) I can't find any evidence that Hernando/Fernando Fernández de Castro's Abt. 1528 to Abt. 1605 (Hernando Fernández de Castro) parents were Fernando Rodriguez Castro, 7th Duke of Lemos and D. Teresa of Andrade Zúñiga and Ulloa, III Duchess of Villalba and Andrade.
2) Real Academia de la Historia (https://dbe.rah.es/biografias/43639/fernando-ruiz-de-castro-y-portugal) states the following in Spanish and my English translation follows):
a) "De su matrimonio con Teresa de Andrade nacieron los siguientes hijos: Pedro Fernández de Castro Andrade y Portugal, que sucedió en la casa de Lemos; Nuño, fallecido siendo todavía niño; Francisca, casada con Rodrigo Jerónimo de Portocarrero, IV conde de Medellín; e Isabel, celebrada poetisa, casada con Rodrigo de Moscoso, IV conde de Altamira. Fuera del matrimonio, Fernando dejó además a Dinís, Rodrigo, María y Polonia."
b) From his marriage to Teresa de Andrade the following children were born Pedro Fernández de Castro Andrade y Portugal, who succeeded to the house of Lemos; Nuño, who died as a child; Francisca, married to Rodrigo Jerónimo de Portocarrero, 4th Count of Medellín; and Isabella, a celebrated poetess, married to Rodrigo de Moscoso, 4th Count of Altamira. Out of wedlock, Ferdinand also left Dinís, Rodrigo, María and Polonia.
3) As you can see from the above, the children born out of wedlock are even listed, and this does not include Hernando/Fernando Fernández de Castro Abt. 1528 to Abt. 1605.
4) Geneanet (https://gw.geneanet.org/fedegrifo?lang=en&iz=33&p=hernando&...) makes the same mistake, which points as it's only source of reference as FamilySearch Family Tree, which can be seen here https://www.familysearch.org/tree/person/details/GLL4-K8M, here https://www.familysearch.org/tree/person/details/G2N3-S5B, and here https://www.familysearch.org/tree/person/details/K1DP-186, and there are no sources that indicate a parent child relationship whatsoever.
5) Wikipedia makes also makes no mention of Hernando/Fernando Fernández de Castro as a son of Fernando Ruiz de Castro and Portugal https://es.m.wikipedia.org/wiki/Fernando_Ruiz_de_Castro_y_Portugal
Ruiz de Castro and Portugal, Fernando was the IV Count of Lemos, which apparently is well documented, and yet Hernando/Fernando Fernández de Castro's Abt. 1528 to Abt. 1605 is nowhere to be found as a son: even as an illegitimate child. As such, I suggest the parents be disconnected- that is both Fernando Rodriguez Castro, 7th Duke of Lemos and D. Teresa of Andrade Zúñiga and Ulloa, III Duchess of Villalba and Andrade as the parents of Hernando/Fernando Fernández de Castro's Abt. 1528 to Abt. 1605.
By the way, there IS documented evidence that Hernando Fernández de Castro's Abt. 1528 to Abt. 1605 was a real person, because at least two of his sons: Juan and his brother Hernando de Castro registered at Casa de Contratación (House of Trade) of Sevilla, Spain for passage to Santo Domingo in the New World as “sons of Hernando de Castro and Teresa Figueroa, natives of Caceres”. Source: (Catalogo De Pasajeros A Indias Volumen II page 30 #500)https://archive.org/details/CatalogoDePasajerosAIndias_Volumen_II/p....
-fbp
