I'm currently experiencing exactly the same issues as mentioned by the topic starter.
Could you provide detailed guide on how to solve this problem? Remote access is not an option due to security policies.
Please make sure something for me at first:
1.How many gateway you have in the same lan network?
2.In automatic cluster page,the firmware version of all master and slave boards are the same or not?
3.Try to access other slave board with format like that:master board ip/slot number/
For example,when the ip of your gateway is 192.168.10.1,you can access slave 2 with 192.168.10.1/2/
Check the "SYSTEM ---> Status" page to see if the module information of each module is normal or not.
It is very conveneient if we can contact via skype.