The bug
Since 1.19.4-rc1, display entity's previous state for interpolation doesn't change most of the time when it should change. I don't know how it works at all: the animation always plays in an unexpected way.
Not sure if this is the same issue with MC-260874 and MC-260885.
How to reproduce
/execute positioned ^ ^ ^4 run summon block_display
/data merge entity @e[type=minecraft:block_display,limit=1] {block_state:{Name:"stone"},transformation:{scale:[3.0,5.0,2.0]},start_interpolation:0,interpolation_duration:0}
/data merge entity @e[type=minecraft:block_display,limit=1] {transformation:{scale:[10.0,10.0,10.0]},start_interpolation:0,interpolation_duration:1000}
waiting for 5 seconds, notice that the stone is becoming big.
Re-run the second command to reset it to 3x5x2
Re-run the third command to restart a new animation
❌ Notice that the animation doesn't reset or restart even with step 5 & 6. Instead, the original animation in step 4 is resumed
Can confirm