When I tap on hide my email in the iCloud section of settings nothing pops up
Tested it on my iPhone with iOS 26 Beta 4, took a while to open, but it worked just fine.
You could try signing out and back into iCloud to see if that fixes it.
It doesn’t work when I restart my phone or sign out and back in to iCloud even when I try iOS 26 Developer Beta 5
You can submit a feedback to Apple using the Feedback app. In the meantime, you can use this feature on the web: iCloud+ (Plus) - Apple iCloud
I did already submit feedback in the feedback app and Apple hasn’t fixed it or reached out to me for clarification
They have a lot of feedback to go through, so please be patient, this is a bug that affects a small number of users, not everyone.