"Safari compact tab layout grayed out on iPhone: iPhone 13 Pro iOS 26.2.1 [...]As I mentioned in the my original post, the compact tab layout option had been active, but I noticed Safari would switch between compact and top layouts while browsing."
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Thank you for the screenshot.
If operable, then I'd say your all set form here. Just report it.
Report this as a Bug to Apple:
Being that it is inaccessible in Settings, yet is useable on the app, then this seems to be a bug from within the iOS.
Do your Part: Provide Apple with feedback on this, letting them know about this issue. Apple may not get back to you directly, but the more feedback they receive on this, the more they will know what is occurring, and what bug fixes to include in updates to come. Apple will know nothing of this occurrence, if you don't report it to them.
- Go Here: Feedback - iPhone - Apple
- Select: "Bug Report" for the "Feedback Type"
- Comment: that this all began after installing an update. Include the URL of this thread
- Proceed from there as necessary