At an alchemy table, I try to create a Restore Health potion with Blue Mountain Flower and Wheat only but instead it just defaults to Fortify Health and creates that instead. I have two characters and this was happening on the new one.

I just now tried it with my old character, that is, trying to create a Restore Health potion with Blue Mountain Flower and Wheat only and it also defaults to Fortify Health.

Seems to be a general bug across characters.

The potion might be called "Potion of Fortify Health," but it will also restore your health. Both of those ingredients have a Fortify Health and a Restore Health element. (Unless you've installed a mod that changes ingredient effects.)