For anyone looking to fix this - attached are scripts to have a work around. (thank you, claude)
Hello @teidetechconsulting, we're using one issue report per unofficially supported game title, so I've gone ahead and transferred this issue report to https://github.com/ValveSoftware/Proton/issues/6852#issuecomment-4076909501.
proton experimentalx1 2026-03
bugs.winehq.org/show_bug.cgi?id=59540
This affects for example the game "Call of Duty - Black Ops: Cold War" - which runs with Proton Experimental.
Bug in the game: Once entering a "Text" Mode (as in Chat, or mini-puzzle in the game) - keyboard context is lost with the game - game needs to be restarted.