Note blocks do not respond to redstone and pitch never changes on player interaction

Expected behavior

Note blocks should play sound and change pitch when right-clicked, and should respond to redstone signals (activate sound + trigger an observer-detectable block update), as in vanilla and as documented for Paper/Folia (NotePlayEvent triggered by player interaction or redstone current).

Observed/Actual behavior

Note blocks on our server do not behave correctly in two ways:

1. Redstone activation (lever, button, redstone block) does not trigger the note block at all — no sound plays and no block update occurs.
2. Manual right-click interaction plays a sound, but the pitch never changes between consecutive clicks (it should cycle through pitches as in vanilla), and no block update is generated — an Observer placed directly facing the note block never detects the change.

This was tested with a freshly placed note block (not a pre-existing/legacy one), ruling out corrupted block data.

Other redstone-powered blocks (dispenser, piston, doors) work normally with the same lever/redstone source, confirming this is isolated to note blocks specifically, not a general redstone failure.

Steps/models to reproduce

1. Place a brand new Note Block in survival or creative.
2. Place a Lever or Button adjacent to it and power it. Result: nothing happens (no sound, no block update).
3. Right-click the Note Block directly with an empty hand multiple times in a row. Result: a sound plays each time, but the pitch/instrument never changes across clicks.
4. Place an Observer directly facing the Note Block (adjacent, same region/chunk). Result: the Observer never pulses, whether triggered by redstone or by manual interaction.

Plugin and Datapack List

Server is running ~60 plugins (Paper + Bukkit type). Full plugin list available on request; core suspects (Vulcan, TotemGuard, WorldGuard, CMI, Skript/SkBee) have already been ruled out via testing described above. Notably, packetevents and ProtocolLib could not be cleanly isolated via hot-unload (PlugManX leaves a broken classloader for these), so a clean test (jar removed + full restart) is still pending on our end.

Folia version

This server is running Folia version 1.21.11-14-ver/1.21.11@529aabc (2026-02-22T20:22:23Z) (Implementing API version 1.21.11-R0.1-SNAPSHOT)

Other

• Tested with air directly above the note block (not silenced by a block on top).
• Tested outside of any WorldGuard region (no region protection in the area).
• Verified no permission node is blocking interaction (LuckPerms wildcard permission confirmed via /lp permission check).
• Disabled the following plugins one at a time (via PlugManX unload, confirmed reloaded after each test) with no change in behavior: Vulcan, TotemGuard, WorldGuard, CMI, Skript, SkBee.
• Inspected decompiled bytecode/strings of SmartSpawner, HamsterAPI, and MythicTools — none reference NoteBlock, Instrument, or redstone-related classes; ruled out as causes.
• Confirmed other redstone circuits (dispenser, piston) work correctly in the same world, same region, with the same lever.
• Confirmed server is on the latest available build for this Minecraft version (output of /version: "You are running the latest version").

This is consistently reproducible — it is not an intermittent issue and has been present since the note blocks were first placed on this server (i.e., not a regression from a specific recent change on our end).

Start by reproducing the note-block interaction and redstone cases described, checking NotePlayEvent behavior and whether an observer detects the resulting block update. Compare player interaction, lever/button/redstone-block activation, pitch changes, and observer pulses; the issue is done when these match vanilla and the documented Paper/Folia behavior in a clean server test.