I recently came across this information which may be of use regarding fit notes. When my husband was denied esa they wrote to him to tell him not to get any more fit notes from his doctor, they also said they would be writing to his doctor to tell him there was no reason to issue any more. Our doctor is excellent and we r now going to appeal backed up by sick notes, but some doctors won’t issue further notes because they think they have no need to. If you are appealing, this fact sheet from Benefits And Work sets out the legal position
https://allequal.xyz/esaGP1