My Group FaceTime calls don’t ring on the receiving end

My Group FaceTime calls don’t ring on the receiving end. However, if I call recipients one at a time, their end rings and they pick up. It doesn’t matter who I call (my parents, sister, or in-laws) or if I call from my iPhone 12, my wife’s iPhone 12, or either of our iPads Pro. All of our devices run iOS 14.x (this has been happening since January and I haven’t noticed a change across updates). The receivers all use new iPads (we bought the family iPads in January to FaceTime with our daughter), but lack the skills (and we lack the patience) to help troubleshoot. Is there a fix for this?