Window snapping is not working under Big Sur beta 5 (20A5354i) with BTT (3.402) in Preview.app when multiple images opened in a single group. It's working fine when only one image are open in that window.
How to reproduce:
- configure Preview.app to "Open groups of files in the same window"
- open at least 2 image from a Finder window
- Type of Mac: MacBook Pro 2018 (4 TB3)
- macOS version: 11.0 20A5354i
- BetterTouchTool version: 3.402