UserDefaults和If / else不稳定的行为

I'll try to explain the best I can the issue(s) Im having: I have a todo list with two viewcontrollers, you will see in the code below a few print for the debug and I added a "erase" (erase userdefault) and check (check whats stored in userDefaults) for debuggingI'll try to explain the best I can the issue(s)