The bug
Observers do not activate when the following changes happen:
Missing a block property in bedrock
Campfire becomes a signal fire (hay block placed below)
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)
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)
Property/block change is not detected
Adding an eye of ender to a portal frame
Vines growing
Vines spreading to another face of a block
Snow layers generating from snowfall
Fixed
Fire catching on another face of a block(fixed in 26.50)Fences/panes/bars changing connections(fixed in 26.50)Stairs changing shape(fixed in 26.50)Tripwire changing shape/connections(fixed in 26.50)Locking/unlocking a repeater(fixed in 26.70)
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
Linked issues
is duplicated by 9
MCPE-177740
Observer Doesn't "See" Vines Growth
Resolved
MCPE-170630
Observer do not active with note block
Resolved
MCPE-120652
Observers do not detect snow falling ontop/to the side or it.
Resolved
MCPE-118969
Observers not registering certain block changes
Resolved
MCPE-112939
Jukebox doesn't give a block update when playing a disc
Resolved
relates to 13
MCPE-30544
Observer doesn't detect curved rail changing direction
Reopened
MCPE-41074
Observer not detecting netherwart growing
Reopened
MCPE-46345
Observers do not detect an entity entering/exiting a bed
Reopened
MCPE-53919
Observers don't detect changes to Note Blocks
Open
MCPE-75742
Observer doesn't detect Respawn Anchor charges
Reopened
Attachments
Comments 29
None of the "block updates" stated are block updates. The problem does not come from the observer. You can test it using other BUDs, they won't detect them either, meaning they aren't block updates.
This has to be the most annoying bug for most redstone players. Redstone in general needs an overhaul in bedrock edition to let people play seriously, post main game.
(Tested before reported - from 'Technical Bugs List' https://docs.google.com/document/d/1nziKYzCr4pBdCRj2gIMlfr9MVdWHd6HyafdiBHx9F0c/edit)
This issue happens in 1.15.0.53 also.