If it’s a mobile device on a wifi network, you may be able to reset your IP by selecting to forget network under your wifi settings and the adding the network back immediately after. If you’re on provider data, switching to airplane mode for a minute may or may not do it. On a home computer you could reset your router.
Obviously only as a workaround because it’s unideal, but until you can communicate with the site admins about it, maybe that will help get you logged in when you get the error.
It’s probably worth mentioning your issue in the main site update thread too, just in case anyone else is experiencing similar.
Hope you can get it fixed!