[iOS26 Bug] UITableView AutomaticDemension not respected unless backgroundColor is set

I discovered a layout issue in iOS 26 Beta that affects dynamic table view row height.

When using rowHeight = UITableView.automaticDimension, the cell height is not calculated properly unless I explicitly set a backgroundColor (even .clear) on the cell or its contentView. This only occurs in iOS 26 Beta. Works fine in iOS 18 and earlier.

You can find a sample project reproducing the issue here:
🔗 Sample Project on GitHub

Conditions

• TableView rowHeight is set to .automaticDimension
• Cells use Auto Layout and have intrinsic content sizes
• No heightForRow override
• Setting self.backgroundColor = .clear in awakeFromNib() fixes the issue

Questions

• Has anyone else experienced this?
• Could this be a bug in the new layout engine for iOS 26?
• Any official guidance?
• Also, if there’s something wrong or fragile about how I set up the layout, I’d appreciate any feedback!

Thanks!