"/execute align" works wierd

/execute at @e[nbt=

{shake:1b}

] align xyz run summon falling_block ~ ~-1 ~

{Block:"minecraft:sandstone",Motion:[0.0,1.5,0.0]}

throws sandstone block under the arrow, but when block lands, it slides to ~-0.5 by x and z.
and falling block just stays there not droping or transforming into normal