On a server in 1.14. When going into spectator mode it doesn't show any blocks whatsoever, only entities. Reloading all chunks doesn't fix the issue, I have also tried waiting around for a while and nothing is loading then either.
On the F3 screen it shows that the biome is "waiting for chunk"
If you relog when in spectator it leaves you frozen in one position unable to move, mobs seem to be shaking around. I have a video attached showing everything I have explained