I changed the Sequence type to "Once", since the explosion should play once. Perhaps this is the reason.
I have added the verification, otherwise I will get a crash. But I'm not sure if it working good, for example, if there are any memory leaks
Attachment* slotAttachment = slot->getAttachment();
if (slotAttachment && (slotAttachment != _attachment)) {
if (!slotAttachment->getRTTI().instanceOf(VertexAttachment::rtti) || ((VertexAttachment*)slotAttachment)->getTimelineAttachment() != _attachment) return;