When changing arrow motion or rotation of arrow with new "store" subcommand arrow will behave different on client side and different on server side. For example when summoning nogravity arrow with no motion it will stand still. When you apply motion to it it will stay still and sync it's position once per second. On server side it will fly as expected which can be checked with "/data get entity" command.
Arrow should sync not only position, but also motion, rotation and all entitydata to fix this. It also should sync it more frequently (once per 5 gametics at least). This is also the case of:
MC-67521 (life not synced)
MC-99442 (entitydata at all not synced)
MC-111533 (probably - not synced type of arrow)
MC-71426 (life not synced)
MC-103426 (NoGravity tag not synced)
and so on...