@HandokoF 

  @d0ugmac1 That's the method I've used to migrate indeed. 

  @HandokoF 

Do you also have a router in software controller side?

Did you check whether the internet in this side is working fine？

  @Virgo 

the internet connection is stable and fast. It's inside a huge data centre with my own static op address fully open. 
 

The server is a windows machine with windows server 2016 installed on it and I've opened all the firewall ports used by Omada. The server isn't behind an Omada router though. I assume that's not a problem. 
 

I'm able to adopt my devices but after a couple of hours my router will go offline and have to connect it to my local OC200 which I'm trying to get rid off

  @HandokoF 

This does seem really odd. I've used my OC200 to remotely managed Omada AP's on a DDNS IP before and that worked pretty well.

Is there anything in the DC controller's logs?  Can you still ping your router from the DC even when it shows 'Disconnected'?  For the 'remote controller' did you use DNS or IP for the controller ip?

  @HandokoF 

I think you might be suffering from the same thing as is going on here....fix coming:

https://community.tp-link.com/en/business/forum/topic/599374 

  @d0ugmac1 

Thanks! It really looks like the same problem. The only difference seems that I'm already running FW2.1.2 on my router and that was the fix for him. Hope the devs will fix the problem soon.