The band might need to be slightly more light for the toning to take. In this picture it looks dark but maybe it’s the light? I’d bleach and retone the areas that are brassy. You can also use a blonde dye to try and get it even. That’s worked for me in the past.
You need to tone it for like 5min
Yes just bleach and tone the bits that bother you. You’ll only need 5, 10mins max depending what strength peroxide, 20, 30 or 40% etc.