Hello there
I encountered a bug, where after loading my single player skirmish save file (Holy Roman Empire in Imperial Age), my mangonels had a ridicoulosly high attack speed of 0.62. Although this was super OP, it was quite amusing to observe these machine gun mangonels obliterate armies in an instant or hear them proudly rejoice after grinding a single passing villager to dust. 
The animation was bugged aswell: The arm of the mangonel was back down in horizontal position instantly.
I have overwritten the original save file with a later save. I reloaded the later save multiple times and most of the time, the bug was reproducable.
I don’t know if it is of any importance, but some prelates stood next to the mangonels at save time, and the mangonels were inspired when loading the save.
I did not succeed to record them in action, but bellow I provided screenshots, which show the broken attack speed (Angriffsgeschwindigkeit) stat:
My game build is 7.0.5976.0 from Steam in German.
Best regards
Jerling