See other recent threads on bloom, like Selective bloom not working - #8 by arjun_lokesh. We don’t recommend using selective bloom if you can avoid it. Instead set a bloom luminance threshold >> 1, and when hover is triggered on an object, increase its emissive value to something much greater than the threshold. For example you might set the luminance threshold to 2, and set the hovered object’s emissive intensity to 100.
EDIT: A longer explainer —