Yep, same thing happened for two people in the past.

They had to "update" the wallets, version, by version from Github.

You probably still have the original version from back 3 years ago.

If you updated from the site, then make another backup, just in case.

I presume you have a backup from the original wallet too.

It will take a little bit of time, but once you do it, your issues with the connections will definitely be taken care of.

The only other thing that pops to mind is that "maybe, just maybe" you are trying to hook up via a dead "witness". Not sure where to update "witnesses" as that is usually in the "Chat" service in the wallet. I doubt that will fix it, but one never knows, could be something as simple as that.