Are you using the mission hub?
I have deleted stuff on my mobile crApple, and on the hub, then some of them seem to reappear. But of coarse I mess with the mission hub with about three different computers.
I currently would recommend making / saving you missions with a key code in the first character of the name "mission2200" to "sa_mission2200" or what every you want to try..
Clear the cache on your browsers, and look for clearing something in Litchi on your mobile device, then recheck / refresh.
Let me know, if you come up with a better plan, or if mine works for you...
Rod