Gameplay Ability C++ only unexpected lifetime

Hi there!
Did anyone experienced that gameplay ability created only with C++, without any blueprint activation, ending without any events randomly? Reproduce problem during long montage or long ability active time.
For example override ActivateAbility and use UAbilityTask_PlayMontageAndWaitForEvent::PlayMontageAndWaitForEvent for long animation with subsription to OnCompleted, OnCancelled delegates. Sometimes long animation ends but you did not recieve any events in EndAbility or montage task end events. Better to reproduce if set pause inside debugger.
Someone research it deeper, any suggestions?