Shooting star dragon and red nova dragon can't return to the field in the next end phase

[IKML]

1. Bug description
   [when i activate the effect of negating an attack it work but on the next end phase shooting star dragon and red nova dragon don't return to the field.]

2. Bug reproduction steps

   1.when an opponent monster attack mine i activate the effect “negate an attack” of shooting star dragon and red nova dragon.
   2.Shooting star dragon and red nova dragon leaves the field and the effect of “negate an attack” works fine.
   3.on the next end phase after activating this effect Shooting star dragon and red nova dragon don’t return to the field

3. Screenshot OR error code
   The sections in red that’s the effect that doesn’t work.
   1.

2.

[Lyris]

Was your monster properly Summoned? Was something preventing monster effect activations and/or Special Summons?

[AntiMetaman]

This is a case of improperly summoned synchro. You cannot special summon it from the GY if it was not properly summoned first regardless of any effects that ignore summoning conditions.

[IKML]

ok, i synchro summoned it and the effect worked, thank you very much