SUMMARY It's not possible to type inside the popup search window inside blueprints unless you give Legacy X11 App Support always permission. https://discuss.kde.org/t/enhancement-request-better-x11-keystroke-compatibility-for-professional-software/36825 https://forums.unrealengine.com/t/i-cannot-type-inside-the-blueprint-action-window/2078805 https://forums.unrealengine.com/t/unreal-engine-5-x-under-linux-search-in-blueprints-not-working/782597/4 https://forums.unrealengine.com/t/ue5-3-cannot-input-text-find-function-on-linux-wayland/1799561/5 STEPS TO REPRODUCE 1. Open any blueprint 2. Right click to open search menu 3. Type inside the window without relying on any gimmick that forces the popup window to gain focus OBSERVED RESULT Nothing gets typed in the search bar EXPECTED RESULT Letters/numbers appearing inside the menu SOFTWARE/OS VERSIONS Windows: macOS: (available in the Info Center app, or by running `kinfo` in a terminal window) Linux/KDE Plasma: KDE Plasma Version: 6.4.4 KDE Frameworks Version: 6.17.0 Qt Version: 6.9.2 ADDITIONAL INFORMATION Some users have found several gimmicks to circumvent this problem such as moving the cursor to the top left and then selecting the editor or right click inside the search box then left click to regain focus.
Moving to kwin, which is responsible for UI windows
Please report this issue to Unreal engine. As a Wayland native application, you're not supposed to use X11 for anything... especially not for input while the window in question is not focused.
Hmm, sorry, I was corrected, UE is still an X11 app. I can't explain the bug in that case though.
Seems like it's still an app bug, no?
Could be, but we need more information to be sure.
*** Bug 511679 has been marked as a duplicate of this bug. ***
A possibly relevant merge request was started @ https://invent.kde.org/plasma/kwin/-/merge_requests/8377
Git commit 4dd843cc025fd1c6602cefd532b5c9566c77ff4a by Xaver Hugl. Committed on 18/11/2025 at 23:13. Pushed by zamundaaa into branch 'master'. events: ignore XCB_FOCUS_OUT events by default They cause problems with some applications that do questionable things with override redirect windows. As the event is only needed for other questionable application behavior (apps rejecting focus), and wlroots doesn't seem to need it either, ignore the event entirely. If any problems arise, KWIN_ENABLE_FOCUS_OUT=1 can be set to get the old behavior back. M +10 -0 src/events.cpp https://invent.kde.org/plasma/kwin/-/commit/4dd843cc025fd1c6602cefd532b5c9566c77ff4a