I have two AP One Flex 300Ms both connected to an AP one AC mini via WDS. Both were upgraded from 3.4.x, but are running 3.5.2.
One shows disconnected, one shows connected. Both are configured identically other than their names, their WDS configuration, and their IP addresses.
There are no issues with connectivity as far as I can see, and I have rebooted both units quite a bit without any issues. I’m just concerned that it says Disconnected on the main dashboard and will cause problems in the future. Please see screen shot below.