The bug
Mobs cannot jump blocks, if they are standing on top of shorter than half of the blocks.
Affected blocks
Repeaters
Comparators
Daylight detectors
Sea pickles
Turtle eggs
Carpets
Snow layers
Flower pots
Cauldrons
Attachments
Comments 3
I can no longer confirm as of 20w11a, with all the listed blocks in the pictured format. However, as a related note, mobs can't seem to be able to escape this configuration when they should because players can, and since these can generate in villages cats and villagers get stuck in them very often. Is this a separate bug report, existing or no?
[media]
@@unknown, that is MC-50556.
Can confirm.