Hallo, I've had a problem entering the creative center for a couple of months. I always have a 1,100 ping, which only decreases after about 5 minutes. I usually have a good ping too, but it's that high in creative mode.
Are you on european servers? You can see this in the settings.
First restart your router and try again.
Otherwise try to connect your device to the router via LAN cable - that usually helps.
Nice day!