It's been a few years since my last Glastonbury- 2017! I have tried every year since for both the resales and the main sales but no luck, apart from the last year when I'd got to the registration lookup and was working slowly, it then crashed on the payment page and bounced me out of the checkout process back to the holding screen.
I've always tried with a number of devices connected to various networks (and thus different IPs), I had the desktop on the go conected to my home internet, hardwired, my mobile phone on some ropey 4G and remote desktop session into my work computer where we have a meaty internet connection, and nobody around on a Sunday so I'd pretty much have the entire connection to myself.
Managed to get through to the ticket page on the mobile with a dodgy 4G connection, with a manual refresh per second in Chrome - and occasionally letting the timer tick down on the page to see it had any effect (!). But it worked and the checkout process was much improved this time.
The moral of it all, don't give up hope. Your time will come around once again, even if you don't get tickets for a while.
Edit-I'm also not freshly re-registered, in that I did whatever I needed to do to preserve my existing registration.