I ran an experiment on this bug report. Enchantments on towns were not affected. The enchantments on the hero was. Also, the bug hits after the first turn.
Edit: Regeneration works correctly. I regenerated the correct HP per turn after the glitch appeared. I am not able to test Nature's Cloak. I beleive that this glitch is affecting spells that change stats. All enchantments casted are displayed in the hero's detail page.
What I did was to first clear all enchantments nation wide.
I then put all known enchantments known onto one hero and one town.
Saved the game.
Loaded the game.
Noticed that values were correct.
Hit end of turn without engaging in any battles.
Compare and noticed that values changed. See atached comparison.

Before

After
