Many thanks for your help.
Can I check which lan the OpenVPN network is bound to?
If I want to keep the wifi able to access OpenVPN, does that interface need to stay assigned to the existing lan network?
Then I would create a second lan (called say lan2), and assign the physical ethernet port to that and make any changes to the routing table to allow lan2 to access the UI? If I’ve understood correctly, you’re saying that lan2 would not be able to access the OpenVPN network.