Forumosa Connection Security Issue

I have recently started receiving this message on both my computer and my smartphone. The https in search box has lines through it. I can’t get the site to accept “https”.

“Your connection is not private. Attackers might be trying to steal your information from www.forumosa.com (for example passwords, messages, or credit cards)”

Forumosa is the only site that gives me this message.

They’re currently using a self-signed certificate. It’s no less secure than completely unencrypted, but could be improved.

It happened ever since they moved the site to a new server