GAS: Effect Application Issue

hi! I currently have the following issue, hoping that somebody already stumbled upon this:

I have an instant Gameplay Effect, which adjusts an Attribute using an execution calculation and the magnitude is set using Set by Caller Magnitudes. If I apply this effect to the owning Actor from an Ability on this Actor, I get the warning message FActiveGameplayEffectsContainer::ApplyModToAttribute CurrentModcallbackData was not consumed For attribute %s on %s. and the Attribute doesn’t get changed during Effect application (the GetAttribute() returns 0 in PostGameplayEffectExecute, even though the evaluated data from the passed in FGameplayEffectModCallbackData contains the correct values.

If I set the effect to be periodic with a duration or if I use a modifier instead of an execution, everything works. If I apply the effect from another ASC, everything works. This is only an issue when applying the GE with an execution from an Ability on an ASC to itself. There are no tag conditions which avoid effect application.

After a deep dive, I found that when it works, there is no AttributeAggregator being created. When not working, there is an AttributeAggregator being created for the Attribute.