Why rasa x change the order of form slot

my rasa version is 2.0 before rasa x, my domain.yml config as follow

after rasa x, my domain.yml config as follow I can not understand , why can rasa train change the order of event_form slot? i will be very thankful if someone help me and give me some suggestion, my nlu data is as follow:

This is a known issue that should be addressed in the next release of Rasa X.

@stephens thanks very much