I changed a hardcore world to not hardcore using nbteditor on a server and now when I die it still sets me to spectator mode, however my hearts look normal and the difficult isn't locked to hard.
This is a server, if this isn't an issue im sorry.
I know that we aren't technically supposed to be able to change a world back to survival but its a server and people voted against hardcore forcing me to change it back
1. Invalid as third party software was used.
2. Make sure to change server.properties to not have hardcore on.