Softether and DHCP

I currently have a Softether server running on my OpenWRT which is a non-gateway device on my network. It also doesn't have DHCP running on it.

Connecting to Softether works fine and my gateway assigns an IP using DHCP correctly.

However, if I turn off my gateway's DHCP server and try to use the DHCP server on OpenWRT, I am unable to connect to Softether. I can see in the Softether management console that a connection is made. I believe it's not connecting due to there being no IP assigned but this is a hunch.

Other devices on my network pick up an IP fine from the DHCP on OpenWRT so it's definitely working. If I turn off DHCP and try running a DHCP server on my desktop, then I am able to connect to Softether.

So it seems that for some reason, the Softether server is unable to connect to a DHCP server running on the same box. Would anyone have any pointers as to why this could be happening?

For reference, I am running everything through a VM on a VPC as my network is on CGNAT. For reference, there is more information on this thread including some network outputs

Thanks in advance for any help.