You can also use the command
/serverconfig setspawnhere
to set the world spawnpoint at your location.
For the rare item that sets your spawn temporarily, it depends on what settings you used when creating your world. You can set it to infinite. The default for Standard is 20 times, Exploration is infinite, and Wilderness Survival is 3 times.
If you want to change that, you can use the command
/worldconfig temporalGearRespawnUses -1
That will make it infinite. You can replace the -1 with a positive number if you just want more respawns than 20.
Hope that helps!