Command block don't work in The End

Take a command block in The End, place it and set a command, the cdommand don't work.

Go to the overworld, it works.

The screens show an example with the say command, command has been set. When i'll try to active it, it don't work.

I think the bug affect also the redstone in The End.

I've searched other issues, but none explain the exact same thing i mean.