"John of Aviz" and "Philippa of Lancaster, Queen consort of Portugal"

Hello, Antonio! I think it is because you have double descent from Peter I the Just, King of Portugal

The relationship calculator is set up to give one of each, blood and in-law kinship. Rarely does it show us two bloodlines at the same time.

You are descended from the King through John's half-brother, João de Portugal, duque de Valência de Campos which would make John your uncle as well as your grandfather.

And you are also descended from Queen Phillipa of Lancaster through her husband, your grandfather, John of Aviz

Having double (or sometimes even triple) descents from some of these royal families sometimes overwhelms the limitations of the Relationship Calculator, which has to prioritize so that it can present just one of each (blood and in-law connections).

Dear Debra Denman, many thanks for the explanation. I was a bit confuse. All the best!

Hello Antonio, Debra Denman explained your relationship with these illustrious ancestors so well. Greetings!!!!

João de Portugal, duque de Valência de Campos is my 10th cousin 12 times removed.
Filipa de Lencastre, rainha consorte de Portugal is my 9th cousin 12 times removed.
Peter I the Just, King of Portugal is my 9th cousin 13 times removed.
John of Aviz is my 10th cousin 12 times removed.

Rei de Portugal D. João l de Borgonha 'O Rei da boa memória! is my 14th great grandfather.

They are my 18th Great Uncle and Great Aut