I may able to provide more detail about this. (Although I know it will be fixed in 1.15).
To other person that meet this issue:
Currently I didn't find a way to restore those blocks, but the can be removed by getting pushed by pistons. (shulker boxes would be replaced but chests seems would not)
BG info:
I own a server that runs on 1.14.60. And some of my friends use piston+furnace to duplicate items today (Take items in furnace at the moment it is pushed, you would duplicated those items).
What I found with those some invisible shulker boxes, chests and signs:
The outline(border?) of those are still the same (known from signs);
the particle colors are remain the same with the origin blocks when I try to destroy those blocks by hand;
the blocks will disappear after a piston pushed it (with air at the other side which make it pushable);
crash logs at background shows that the server knows those blocks.
e.g. Crash: at ShulkerBoxBlock::playerWillDestroy[Player&, BlockPos const&, Block const&] const (UnknownFile:?)
Since both the cause and the result are related to block data, I guess this may be caused a memory leak issue?
Colin Yang
I may able to provide more detail about this. (Although I know it will be fixed in 1.15).
To other person that meet this issue:
Currently I didn't find a way to restore those blocks, but the can be removed by getting pushed by pistons. (shulker boxes would be replaced but chests seems would not)
BG info:
I own a server that runs on 1.14.60. And some of my friends use piston+furnace to duplicate items today (Take items in furnace at the moment it is pushed, you would duplicated those items).
What I found with those some invisible shulker boxes, chests and signs:
The outline(border?) of those are still the same (known from signs);
the particle colors are remain the same with the origin blocks when I try to destroy those blocks by hand;
the blocks will disappear after a piston pushed it (with air at the other side which make it pushable);
crash logs at background shows that the server knows those blocks.
e.g. Crash: at ShulkerBoxBlock::playerWillDestroy[Player&, BlockPos const&, Block const&] const (UnknownFile:?)
Since both the cause and the result are related to block data, I guess this may be caused a memory leak issue?