What I expected to happen was...:
Expected that bettwen 179 and 180 there will be a smoth small movment

What actually happened was...:
a backflip

Steps to Reproduce:

1. /summon block_display ~ ~ ~ {teleport_duration:5,block_state:{Name:"minecraft:stone"}}

2. /data merge entity @e[type=block_display,limit=1,sort=nearest] {Rotation:[0F,179F]}

3. /data merge entity @e[type=block_display,limit=1,sort=nearest] {Rotation:[0F,180F]}