PC: Chat window closes immediately or locks keyboard/mouse input

Platform: PC (Windows)

There is a recurring issue when opening text chat where the chat window either closes immediately or causes keyboard and mouse input to stop working while the game continues running.

Alt-tab and Ctrl+Alt+Delete still work, but the game no longer receives keyboard or mouse input. In some cases, controller input still works.

The issue occurs intermittently and worked correctly in previous sessions. Borderless mode is enabled. Rebinding chat off Enter did not resolve the issue.

This appears to be an input focus conflict triggered when opening chat.