Confusing scope of the "Override server address" field
The "Override server address" checkbox does something only when downloading the .ovpn file, otherwise it doesn't do anything.
When I first tried to override the server address, I tried to do so when adding a new client because I wrongly assumed it would pre-generate config files and then just statically download them. I thought it succeeded, because the checkbox got deselected and the entry box disappeared. I think this tiny issue could have been prevented with a bit different design:
a) Don't reset the checkbox and entry box state when adding a new client, so the user doesn't think it succeeded (or at least downloads the .ovpn file with the entry box still filled with the required information).
b) Remove the whole "Add new client" section and add a plus button to the heading of the table which shows a modal with the entry box. This way the user can not get confused where the server address override is effective.