MC-260857 has been fixed, but another similar bug is still there.

Display entities that are summoned with custom transformation will interpolate from the default transformation instead once the next transformation with interpolation is applied.

To Reproduce

1. /execute positioned ^ ^ ^4 summon block_display run data merge entity @s {block_state:{Name:"stone"},transformation:{scale:[3.0,3.0,3.0]}}
   

2. /data merge entity @e[type=minecraft:block_display,limit=1] {transformation:{scale:[10.0,10.0,10.0]},start_interpolation:0,interpolation_duration:1000}
   

3. Notice there's a chance that the display entity resets to the default transformation before performing the new transformation interpolation