Create a test process with an Exclusive gateway with two different end nodes. Set the first flow to "return true;" with priority 1. Set the second flow to "Default flow for exclusive gateway" with priority 10. After that you add a new end node and make the third flow to the new end node. Issue gets reproduced when you set priority 3 and than you click on "Add Condition" and Set "return false;" Upon click of Add Condition button, the default flow marked goes away for end node which was set default prior to adding the third new end node. "The "Default flow" that was set goes away and has to be reset.