I exited the nether and set my respawn point by clicking on a bed (daytime) then went in the water and was killed by a drowned with a trident.  When I respawned I fell out of the world.  The x/z coordinates are the same as my bed, but y coordinate seems to be y=-1.

Checked in database, and my spawn coordinates are correct, but I'm just appearing under the bedrock.  See attached files

I experienced this before when exiting the end by gliding through exit portal on elytra.