Some blocks don’t have the correct hitbox in bedrock edition. The following blocks are affected (list may be incomplete):
Anvils (MCPE-59921)
Beds (MCPE-60829)
Bells hanging on the ceilling or side of a block
Brewing stand (MCPE-59922)
Cauldren (hitbox doesn’t go inside it)
Composter (hitbox doesn’t go inside it)
Fences, Iron bars, walls and glass panes on a corner (MCPE-59920)
Grindstone
Hopper (MCPE-47541) Fixed in 1.16 beta
Lantern
Lectern (MCPE-47604)
Levers
Piston body (When it is extended) (MCPE-83258)
Redstone (MCPE-61245)
Sea pickle (MCPE-59925)
Sugar cane (MCPE-60827)
Walls (MCPE-55865)

This also relates to MCPE-59928, where the outline doesn’t match the hitbox on some blocks.