Mod Version: v1.20-2.5.15
Minecraft Version: 1.20

Blaze frequently ignore bellows, this does not apply to all blaze, but i'd say 1 in 10 blaze just do not get pushed by bellows.
This can be replicated by setting up bellows around some blaze spawners to push the blazes away. After about 10 - 15 minutes most blazes will be sitting in the airflow of bellows but being uneffected

Could he that they are actively walking closer to them

Must be some quirk of blazes themselves then, something related to their hovering behsvior that makes them not react to pushes

@MehVahdJukaar no, while sometimes they do these blaze are not moving at all. the ones that are actively walking towards them do get pushed back then move forward and repeat that, these stuck blazes have zero motion at all

Is this issue related to Supplementaries?