Paul Noad

This is happening quite often in realms although seemingly at random.  When entering the overworld into an area underground that has since been cleared the game initially renders the stone that was part of the seed before updating a few seconds later.  In the nether if you have a portal on a raised platform there is a chance of falling past the floor before it has a chance to render.  I recently took a swim in lava due to this issue.

I have encountered this issue multiple times on our realm since the 1.21.23 hotfix.  It affected half of the hopper minecarts under my bamboo farm running on west to east rails.  The carts would all stop on the regular rails just before the power rails that were used to launch them at the west end of the line (powered or unpowered made no difference).  Initially breaking and replacing would fix the issue, but eventually that fixed stopped working.  After I replaced the broken half with hopper minecarts directly over hoppers the other half ended up breaking the same way.

After that I discovered that the hopper and chest minecarts on our super smelter were also getting stuck.  These were on north to south rail lines.  On one level the cart on the west rail worked perfectly while the one just next to it stopped on a random powered rail about half way down the line.  The other 2 carts were stuck on the regular rail just past the initial launching point.  On the lower level all 4 carts were stuck on the regular rail just past the launching point.