Not sure where your father is in his recovery. But if its within 2 years then yes this is normal. The recovery phase can be full of ups and downs with it being a long, slow process. Set backs are common, mostly during the first 6 months post rads (if he had that???). If you feel he is really starting to struggle then he should be checked out by a doctor.

Many patients have a barium swallowing test done to ensure they are not aspirating when drinking and eating. After going thru rads, many have swallowing problems. Seems like those who didnt swallow several times a day fare the worst.

Please add a signature so its easier to help you with your questions. Ive sent you a link which gives detailed info on how to add it.

Thanks and best wishes!