When checking to see if a Minecraft Map would continue to function after updating it to 1.21.10 we discovered a bug with redstone repeaters that was not previously present in Minecraft. This is an abnormal situation that can only be accomplished using commands and would not happen in survival Minecraft likely but nevertheless it is present. I have created a video demonstration that better outlines the issue as it is difficult to explain without it. Essentially when a powered lever is artificially removed from a powered block and replaced with an unpowered lever (using a command such as /clone or /setblock) the repeater remains in a powered state despite there being no powered block behind it. This appears to only occur when the repeater is directly powering a block with redstone dust adjacent to it in any direction. The demo only video was taken in single player vanilla Minecraft.
Quick Demo (Singleplayer Local Vanilla Minecraft): https://www.youtube.com/watch?v=q8I78LDj5UU
Explanation Video (Paper Server on offsite machine): https://www.youtube.com/watch?v=a2TY8Ic78HQ
Environment
Single player vanilla Minecraft, occurs on all server software including forks such as spigot or paper as well.
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We're tracking this issue in MC-31100, so this ticket is being resolved and linked as a duplicate.
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