Ignition Connect to Siemens OPC-UA

I have 1 siemens PLC, 1500 brand, it have the opc-ua inside, it is in the same IP with Server , as the upside picture i have success connect to it .

but in the real production line, the PLC IP is 172.16.127.2, i need use a NATR to switch it to the same ip as the ignition server,

this is when i configure the

most of the case it will shows

but sometimes the step4 can show as the following picture

it will failed at step6

but i use kepware to read

it can browse the tags by means of OPC-UA

TAG READ IS OK

My question is , if the kepware is ok , that means the plc and network should be ok , but why ignition failed, how to set ignition successfully read the opc-ua tags?