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 iron bars).

Affected blocks list (maybe incomplete):

• Wall
• Fence
• Fence gate
• Stairs
• Door
• Trapdoor
• Iron bars (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 soul variant
• 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
• 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

Steps to Reproduce:

1. Place a spawner/trial spawner.
2. 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.