You didn’t miss the red flags. You picked out a nicer color and repainted them.

Warning signs usually get registered and then reinterpreted, because the alternative is losing something you wanted. You explain the behavior with context, with their bad week, with the version of them you have seen before, and each explanation is individually reasonable. That is not stupidity; it is what hope does to evidence.

If you catch yourself building a case for someone, write down the plain facts with no interpretation attached. Read them as though a friend had brought them to you. You may still decide to stay, and at least you will be deciding with the original colors visible.