Research skill stuck

[isoka]

You can do research at level 16, but you won't be able to raise your skill to the trivial level skill for level 16 spells. So expect some failures !

Each level you earn will raise your skill cap by 5.

The fact that your skill is at 17 right now is because you unlocked the skill at level 17 and when you unlock a skill, it often gets as high as your level when you unlock it.