I just had the same issue. GreenGeeks said it was my ISP provider. I called ISP and they insisted it wasn’t them. I called a friend with the same ISP provider and they could access my website from their IP address, so the issue was IP address. ISP allowed me to change my IP once and they did it from their end. As soon as IP address was changed, I could log in to my wordpress website and admin panel. When I asked ISP’s technical support what they thought it could be, they had no idea.
Anyway, if you have trouble accessing your website or it’s admin panel and your browsers keep saying “connection timed out”, try to change your IP address. That should hopefully fix the problem. As far as the source of the problem, I could not find out what it was from my end since both website host and ISP were saying it wasn’t an issue at their end.
If anyone has any idea why this could happen, let me know so I know if this could be prevented from happening in the future.