Transmitter doesn't activate when only on block of redstone
Bug report
I'm using version: v4.0.4 I'm on Minecraft: 1.14.4 I'm running: Paper version git-Paper-209
Seen results:
When activating a transmitter with a lever connected to it with only one redstone block between, the signal is not transmitted and the receiver doesn't activate.
Expected results:
The receiver should activate.
How to reproduce:
Place a lever, then redstone, then a sign. Make a transmitter with the sign.
Place a receiver somewhere else.
Activate the lever ; the receiver doesn't get activated.
Additional info:
Place the lever right next to the sign and everything works as intented.
Place the lever with two redstones then a sign and everything works as intented.
The following gif quickly show the issue.

I can't reproduce this bug, can you try it again on the latest Paper build?
This still happen to me with Paper's build 225.
Additionnaly with the latest Paper build I get this error whenever a sign turns into a torch :
[Server thread/ERROR]: Block at 78, 47, 154 is Block{minecraft:redstone_torch} but has net.minecraft.server.v1_14_R1.TileEntitySign@7a537520. Bukkit will attempt to fix this, but there may be additional damage that we cannot recover.