Minecraft 17w18b, Minecraft 1.12 Pre-Release 1, Minecraft 1.12 Pre-Release 2
Windows 10, embedded Java.
I am using a /fill command on an one second clock to convert all emerald blocks (in a big area) into redstone blocks and back. However, the redstone dust and command blocks connected to the replaced emerald block won't update after setting it to redstone. It worked in previous snapshots.
Replacing the block by hand works.
Replacing the block using /setblock works.
Replacing the block using /fill works (all blocks in an area).
Replacing the block using /fill replace doesn't work (tested with both subid 0 and 1, both air and emerald blocks).
As I said, the clock runs once a second so the redstone should have time to update.
I ran through all the latest versions of snapshots in every week, 17w17b was the last one that worked properly.
EDIT: I also tried replacing the attached redstone wire, thinking it might be a bug with block conversion between versions. This didn't help.