After updating to macOS 26.3 Release Candidate, all interactions for borderless windows are no longer working. In macOS 26.3 Beta, borderless windows behaved correctly: • Mouse clicks were received normally • Window dragging worked as expected • Interaction logic was fully functional However, in macOS 26.3 RC, all of the above behaviors are broken: • Click events are not delivered • Windows cannot be moved or interacted with • The issue affects all borderless windows This is a regression from the Beta build and appears to be system-level, not app-specific. Environment: • macOS: 26.3 RC • Window type: borderless / frameless windows • Status in 26.3 Beta: working correctly • Status in 26.3 RC: completely broken Could Apple confirm whether this is a known issue or an intentional behavior change in 26.3 RC? If this is a , is there a recommended workaround before the final release? Thanks.