Update instantiate_util.py

asyncua/common/instantiate_util.py

@@ -98,7 +98,7 @@ async def _instantiate_node(server,
                                     c_rdesc.BrowseName, addnode.BrowseName)
                         continue
                         # exclude nodes with optional ModellingRule if requested
-                    if not instantiate_optional and refs[0].nodeid == ua.NodeId(ua.ObjectIds.ModellingRule_Optional):
+                    if not instantiate_optional or refs[0].nodeid == ua.NodeId(ua.ObjectIds.ModellingRule_Optional):
                         logger.info("Instantiate: Skip optional node %s as part of %s", c_rdesc.BrowseName,
                                     addnode.BrowseName)
                         continue