Skeleton arrows do random damage no matter how far away you are from the skeleton from shooting faster. 

According to the Minecraft wiki, Bedrock Skeleton's attack strength is depending on proximity which should mean that skeletons that are far away from you should do the most damage to you while skeletons that are very close to you should do the least amount of damage to you.

How to reproduce: 

1. Spawn a skeleton if needed.
2. Get close to the skeleton (at least 1 block away from it)
3. Let the skeleton shoot you
4. The damage would be completely random despite the wiki saying that it depends on proximity.

This issue also applies to strays.