Observer doesn't detect several block state changes

The bug

Observers do not activate when the following changes happen:

• A campfire becomes a signal fire (hay block placed below)

• Adding an eye of ender to a portal frame

• Fire catching on another face of a block

• Vines growing

• Vines spreading to another face of a block

• Fences/panes/bars changing connections (works for walls, see also MCPE-71925)

• Stairs changing shape

• Grass becoming snowy (snow placed on top)

• Adding/removing a music disc from a jukebox

• Adding/removing a book from a lectern

• Leaves distance changing (log placed nearby)

• Locking/unlocking a repeater

• Tripwire changing shape/connections

• Snow layers generating from snowfall

• Note block changing instrument (block below changed)

• Powering/unpowering a note block

• Powering/unpowering a door/trapdoor that's already open

• Powering/unpowering a mob head (works for piglin/dragon heads, but not others)

Related issues

• Powering/unpowering a hopper: MCPE-40843

• Pumpkin/melon stems moving: MCPE-36783

• Nether wart growing: MCPE-41074

• Note blocks changing note: MCPE-53919

• Entering/exiting a bed: MCPE-46345

• Rail changing direction: MCPE-30544

• Respawn anchor charged: MCPE-75742

• Target block getting hit: MCPE-84391

• Kelp age changing: MCPE-179683

• Various fixed issues: MCPE-14710