This happens far too often, Apple.
Considering the price people have to pay & the hoops people need to jump through to use your platform, you'd think it would be a hell of a lot more stable than this.
It literally happens every few months - blocking a tonne of developers with work to do:
https://www.google.com/search?q=app+store+connect+Sorry%2C+something+went+wrong.+Try[…]MVjaARwAXgAgAEziAFjkgEBMpgBAKABAaABAsgBCsABAQ&sclient=gws-wiz
This literally never happens with Google's Play Store.
But is a consistent, persistent issue with App Store Connect.
And even when it is up & working, it is the slowest, most cumbersome & clunky website I have ever had the displeasure of being forced to use.