Brick moulding around windows pulling away from brick. Best fix?

I’m in the process of replacing my old wood frame windows with new vinyl. The brick moulding around several windows has completely separated from the brick and even sunk on one of them (tried to picture) and wondering what would be the best possible fix performance wise and visually.

It’s possible the brick itself shifted and pulled away from the moulding, I’ve had some foundational work done already.

Any ideas? We have considered getting new moulding and a new sill and perhaps using some additional strips of wood to fill the gaps but I’m not sure that will work out visually.