When the host player is in the process of opening to LAN, they are able to set the default gamemode and enable cheats.
Steps to Reproduce:
1: Open the Pause Menu in your Minecraft Hardcore World
2: Click the Open to LAN button (Make sure you are not already hosting your world; if you are, reload the world.)
3: You can set the LAN settings for other players just like any other survival or creative world.
Observed Results:
You will be able to set your gamemode and enable cheats when you click Open to LAN.
Expected Results:
When you click on Open to LAN, it should open the game to LAN, keep the gamemode set to survival by default if the player is alive. If a player is spectating and they had left the game & you reloaded the world, they would still be in spectator mode when they join back in.
Note: I did search for other issues like this, and I have not found any so far. If an issue like this has already been submitted, please let me know! Thanks!
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Thank you for your report!
We're actually already tracking this issue in MC-134, so I resolved and linked this ticket as a duplicate.
However, that ticket has already been resolved. Depending on the resolution, that can mean that it either will be fixed in the next version, or that it is not considered a bug and won't be fixed.
If you haven't already, you might like to make use of the search feature in the future to see if the issue has already been reported.