Are you nodes ssl or non-ssl.
If they are non ssl nodes, there's no point of putting https monitor, it will fail.
You gotta try putting http monitor.
Having node ip from the same subnet does not mean it is ssl server. Maybe the one working is having ssl enabled and thats why https monitor is put and like wise a serverssl profile.
But if your current non-working is non ssl, put http monitor and remove serverssl profile.
Try http instead of https.
curl -vk http://[Node IP]
If your http/https monitor is marking it as up and still VS is inaccessible, we can troubleshoot further.