To repro, create a new quick3D project and paste the following code under scene node:
            Repeater3D {
                id: repeater3D
                model: 2
                Repeater3D {
                    id: repeater3D1
                    model: 2
                    y: index * 110
                    Model {
                        id: cylinder
                        source: "#Cylinder"
                        x: index * 150
                        DefaultMaterial {
                            id: cylinderMaterial
                            diffuseColor: "#4aee45"
                        }
                        materials: cylinderMaterial
                    }
                }
            }
 
--> Render puppet crashes:
                                                                                                                          
                                                                                                                           
                                                                                                                           
1   QQmlDelegateModel::componentComplete                                Qt6QmlModels                        0x7ff9d929a449 
2   QQuick3DRepeater::componentComplete                                 qquick3drepeater.cpp            306 0x7ff9cb696a0b 
3   QmlDesigner::Internal::QmlPrivateGate::doComponentCompleteRecursive qmlprivategate_56.cpp           401 0x7ff62ede15d3 
4   QmlDesigner::Internal::QmlPrivateGate::doComponentCompleteRecursive qmlprivategate_56.cpp           389 0x7ff62ede154d 
5   QmlDesigner::NodeInstanceServer::setupInstances                     nodeinstanceserver.cpp          620 0x7ff62ed6dc28 
6   QmlDesigner::Qt5NodeInstanceServer::setupScene                      qt5nodeinstanceserver.cpp       174 0x7ff62edc69ce 
7   QmlDesigner::NodeInstanceServer::createScene                        nodeinstanceserver.cpp          339 0x7ff62ed5cb74 
8   QmlDesigner::Qt5RenderNodeInstanceServer::createScene               qt5rendernodeinstanceserver.cpp 161 0x7ff62edc8d0a 
9   QmlDesigner::NodeInstanceClientProxy::dispatchCommand               nodeinstanceclientproxy.cpp     541 0x7ff62ed03952 
10  QmlDesigner::NodeInstanceClientProxy::readDataStream                nodeinstanceclientproxy.cpp     377 0x7ff62ed0dcee 
11  QObject::qt_static_metacall                                         Qt6Core                             0x7ff9d89417e1 
12  QMetaObject::activate                                               Qt6Core                             0x7ff9d8943974 
13  QLocalSocket::stateChanged                                          Qt6Network                          0x7ffa2f92cd63 
14  QObject::qt_static_metacall                                         Qt6Core                             0x7ff9d89417e1 
15  QMetaObject::activate                                               Qt6Core                             0x7ff9d8943974 
16  QWindowsPipeReader::consumePendingAndEmit                           Qt6Core                             0x7ff9d8a5219c 
17  QWindowsPipeReader::event                                           Qt6Core                             0x7ff9d8a52256 
18  QApplicationPrivate::notify_helper                                  Qt6Widgets                          0x7ff9dfe521ed 
19  QApplication::notify                                                Qt6Widgets                          0x7ff9dfe512db 
20  QCoreApplication::notifyInternal2                                   Qt6Core                             0x7ff9d890a194 
... <More>                                                                                                                 
Preview with nested repeaters works fine.