I have found these small issues in the v101 of the game, playing the Great Northern War against Sweden.
1) In 1701/1702, I have occupied the area of Saint-Petersburg with a russian army, the option "foundation of St-Petersburg" was unlocked. But a small swedish force occupied again this area and I got two options "foundation of St-Petersburg" , one was unlocked and the other was locked.
2) After Denmark left the anti-swedish alliance, you can still build danish garnison units almost everywhere (in Russia, in Poland, ..).
3) After the "Peter rules" option is applied, there are some erroneous elements in the garrison units (example : in Arkhangelsk).. These garrison units don't have any pictures and you see in the unit info panel the word "erroneous" appears.
4) After the "Peter rules" option is applied (?), the russian player gets a new line of replacements : they are called "common" and they have a green colour. It could be good to know where they are used (maybe in the new garrison units ?)
5) The manual furnished with he game doesn't seem the last version.
There is a button "manual" that you get when you launch the game : il conducts the player to a web page where you can download a more recent version of the manual.