Personally, apart from Javier and the higher ups like the King of Hell and messenger, no one would actually believe that Lloyd was replaced. They notice the changes. In fact, they’ve acknowledged that he’s different from what they know of him, but the expression package of the character Lloyd Fontera aka his endearingly “ugly” expressions is kind of what solidifies he’s still the Lloyd they know, just that he matured.
Doesn’t Lloyd’s brother kinda know it too? Javier already shared his suspicions to the brother and he trusts Javier’s judgement. As for the parents, didn’t they also already questioned if that was rly their son? It’s those moments plus more in the novel preludes that they somehow suspect it but definitely not for sure, maybe amnesia at the very least. I think it’s more on this Lloyd is much much better than the ogLloyd that they don’t even wanna think about it plus (SPOILER)
((((((((((OgLloyd and this Lloyd are the same soul so their vibes have somewhat of similarities its just that this Lloyd already experienced a much tougher life))))))))
I kinda feel sad for the og Lloyd, his family knew at the back of their mind that he did get replaced but ignored it because well, the new Lloyd is “better”. The knight knowing is not as sad but the family knowing is just sad.