Holy Roman Construct 3 keeps in influence of the Elzbach Palace Landmark ISSUE

hey, so ive had 3 games trying to get the 12th mastery mission where i have to build 3 keeps within the influence of the Elzback Palace. ive constructed the keeps AFTER i aged up constructing the Elzbach Landmark. The keeps even had a symbol telling me they was receiving the buff due to being within the Palaces influence. However every time i finish the game it still has not given me the mastery completion?? The Holy Romans are my 3rd last civ to complete all the masteries for.
is this a game issue or am i doing it wrong?
has anyone else been having these problems.
This is my first ever bug btw, games ran pretty smoothly so far.


They need to be in influence of your main TC as well.