when the speedrunning the game i came upon a ruined portal i quickly dashed over to look inside the the chest but to my surprise there wasnt a chest besides the ruined portal i then decided to further investigate the seed in creative mode and i came to the conclusion that there was none.
the seed is
3297522141755180711
and the cords are x- +100 y- +63 z- +245
Duplicate of MC-182652, which will be fixed in 1.16.2