Z-fighting occurs between some blocks and spawners/trial spawners. Note that some reports has partially covered this already (MCPE-123732 for azalea/flowering azalea, MCPE-123733 for big dripleafs, MCPE-139214 for leaves, MCPE-168603 for bars).
Affected blocks list (maybe incomplete):
Wall
Fence
Fence gate
Stairs
Door
Trapdoor
Bars and copper variant (MCPE-168603)
Glass and variants
Glass pane and variants
Scaffolding
Slab
Copper grate
Slime block
Honey block
Carpet
Bed
Torch and variants
Sea pickle
Lantern and variants
Candle
Cartography table
Campfire and soul variant
Brewing stand
Anvil
Grindstone
Enchantment table
Lectern
Cauldron
Composter
Chest and variants
Hanging sign
Painting (note that paintings are entities)
Item frame and glow variant
Flower pot
Powder snow
Beacon
Bell
Stonecutter
Heavy core
End rod
Lightning rod
Lever
Button
Tripwire hook
Pressure plate
Daylight sensor
Redstone repeater
Redstone comparator
Hopper
Piston and sticky variant
Banner
Decorated pot
Farmland
Dirt path
Leaves (MCPE-139214)
Cactus (placed with command)
Ice
Top snow
Moss carpet and pale variant
Mangrove roots
Big dripleaf (MCPE-123733)
Small dripleaf
Azalea and flowering variant (MCPE-123732)
Spawner and trial variant (yes... they can z-fight with each other)
Vault
End portal frame
Dragon egg
Sea turtle egg
Chorus flower
Sculk shrieker
Sculk sensor and calibrated variant
Dried ghast
Shelf
Copper golem statue
Steps to Reproduce:
Place a spawner/trial spawner.
Place a block mentioned above adjacent to the spawner/trial spawner.
Observed Results:
Z-fighting occurs between these blocks and spawners/trial spawners.
Expected Results:
Z-fighting would not occur between these blocks and spawners/trial spawners.
Notes: Some blocks will need special placement (e.g. slabs need to be placed on the side instead of top or bottom) in order for z-fighting to occur.
Linked issues
is duplicated by 2
Attachments
Comments 3

Confirmed, Also affects with android.
affected types
Honey block
Slime block
Decorated pot
Stairs
scaffolding
glass, Tinted and colored stain glasses
glass pane and colored stain glass panes
Cartography table
Leaves (MCPE-139214)
Azalea and flowering Azalea (MCPE-123732)
Composter
Cauldron
hopper
piston and sticky piston
Trapdoors
Copper grates
Anvil
Walls
fence
iron bars (MCPE-168603)
doors
Grindstone
hanging signs
Vaults
mangrove roots
Lightning rod
end rod
cactus
chorus flower
Note: this is not a complete list of affected types