i got the "seal" ending a couple of times, where i was only able to use about 5 hands before having to head to the ending sequences. Then i did another new playthrough, where i tried to see some different echoes (but still select them quite randomly) and was able to use 7-8? hands, eventually the game led me to a different ending. Guess i sort of got that 2nd ending by chance?
mmm it shouldn't be possible to do the same ending twice if you continue playing on the same playthrough, or maybe you started a new game after ending the first time? Hopefully, otherwise it means there is a bug somewhere! ahah. When you reach an ending you are brought back to the Chapel, and from there if you continue playing and choosing new echoes you get to a different ending. The three endings are more like three 'chapters', three possible alternatives that together should give a sense of what's going on and the lore. The order they happen can feel random, and that's ok it's part of the game, however there is some very subtle internal logic that connects the echoes to the different endings, but it's pretty much open to interpretation!
thanks for elaborating! as far as i recall, after getting the "seal" ending first time, i chose "continue" the game and got back to chapel, but from there i could still only follow the same fixed ending sequence for "seal" ending again, not sure if it's a bug tho. However, it's not a problem when i start a new game and get the "attunement" ending, where i got prompted in-game that i can continue to experience the game.