These are the only ones I have for my enderman that was nametagged Alastor. I Have taken a few screenshots of a few other mobs, and will keep you updated. Apologies for not having any screenshots at hand.
@Avoma I do not use optifine. It is happening both to myself and friends who use and don't use optifine. Unfortunately, I don't have any screenshots with F3 with the nametagged mobs, so I am checking with my friends and will try to see if we can get some screenshots.
NanoHour
These are the only ones I have for my enderman that was nametagged Alastor. I Have taken a few screenshots of a few other mobs, and will keep you updated. Apologies for not having any screenshots at hand.