"Centralize the Habsburg Empire" in GFM not working
So I was playing Austria in GFM and I wanted to go down the "Centralize the Habsburg Empire" path. The requirements for the decision include you getting the "Prussia lost the Brothers War" global flag and the "The Austrian Destiny" country flag.
I defeated Prussia in the Brothers War and made them drop out of GP. The event for Prussia having lost the Brothers War fired a it it should. However, the global flag "Prussia lost the Brothers War" didn't appear (even after letting the game run for a few years afterwards) – neither did I get the "The Austrian Destiny" country flag. I loaded a prior safe and defeated Prussia in the Brothers War again (without making them drop out GP). Yet, still, the global and country flags didn't appear.
What did I do wrong? Is it a bug?