After rasa train, rasa cannot recognize some actions and it's not following stories

Hey there, I just upgraded my rasa/rasa-x to the newest version…but since the whole week, the rasa seems act oddly. In the beginning everything works rather well and matches my stories, but now after I train a new model, it cannot recognize some actions but my old model still works… I don’t know what’s wrong there, and I tried to switch to the old code of mine, and retrain it, it still doesn’t work…

Does anyone have a clue?

Thanks a lot

from which version to which version did you upgrade?