For me, the combination of SDL_VIDEO_DRIVER=x11 and Slate.EnableTooltips=False in BaseEngine.ini makes the 5.7.1 editor finally normally usable. Clicks register as they should, same as in 5.6.1.
For reference, I’m on EndeavourOS, KDE Plasma 6.5.3 in Wayland session, with AMD RX 7900XT / Mesa 25.2.7.
I’m however getting some stalls related to notifications, with every stall trace going through SDL and X11 calls.
Engine Version: 5.7.1-48512491+++UE5+Release-5.7
Stall Detector: FEngineLoop::Tick
Stall Duration: 7.917857
Stall Time: 2025.12.03-23.38.56
StackTrace
==========
00: [0x0x7f7771ee1710] [libUnrealEditor-Core.so] : [FUnixPlatformStackWalk::CaptureStackBackTrace(unsigned long long*, unsigned int, void*)] : </mnt/horde/++UE5/Sync/Engine/Source/./Runtime/Core/Private/Unix/UnixPlatformStackWalk.cpp>:806
01: [0x0x7f7771ea722c] [libUnrealEditor-Core.so] : [ThreadStackWalker(int, siginfo_t*, void*)] : </mnt/horde/++UE5/Sync/Engine/Source/./Runtime/Core/Private/Unix/UnixPlatformCrashContext.cpp>:1045
02: [0x0x7f776523e4d0] [libc.so.6] : [] : <>:0
03: [0x0x7f776529f002] [libc.so.6] : [] : <>:0
04: [0x0x7f776529316c] [libc.so.6] : [] : <>:0
05: [0x0x7f77652931b4] [libc.so.6] : [] : <>:0
06: [0x0x7f776531c521] [libc.so.6] : [recvmsg] : <>:0
07: [0x0x7f773df278d6] [libxcb.so.1] : [] : <>:0
08: [0x0x7f773df283af] [libxcb.so.1] : [] : <>:0
09: [0x0x7f773df28910] [libxcb.so.1] : [] : <>:0
10: [0x0x7f773df29ba5] [libxcb.so.1] : [xcb_wait_for_reply64] : <>:0
11: [0x0x7f773dfb57ee] [libX11.so.6] : [_XReply] : <>:0
12: [0x0x7f773dfff176] [libX11.so.6] : [XkbGetState] : <>:0
13: [0x0x7f7769d1b3de] [libUnrealEditor-ApplicationCore.so] : [X11_DispatchEvent] : </SDL-gui-backend/src/video/x11/SDL_x11events.c>:1203
14: [0x0x7f7769d1c42a] [libUnrealEditor-ApplicationCore.so] : [X11_PumpEvents] : </SDL-gui-backend/src/video/x11/SDL_x11events.c>:2145
15: [0x0x7f7769c00537] [libUnrealEditor-ApplicationCore.so] : [SDL_PumpEventsInternal] : </SDL-gui-backend/src/events/SDL_events.c>:1457
16: [0x0x7f7769c007e5] [libUnrealEditor-ApplicationCore.so] : [SDL_WaitEventTimeoutNS] : </SDL-gui-backend/src/events/SDL_events.c>:1628
17: [0x0x7f7769ba5ec8] [libUnrealEditor-ApplicationCore.so] : [FLinuxPlatformApplicationMisc::PumpMessages(bool)] : </mnt/horde/++UE5/Sync/Engine/Source/./Runtime/ApplicationCore/Private/Linux/LinuxPlatformApplicationMisc.cpp>:458
18: [0x0x23a7c9] [UnrealEditor] : [FEngineLoop::Tick()] : </mnt/horde/++UE5/Sync/Engine/Source/Runtime/TraceLog/Public/Trace/Detail/Channel.inl>:18
19: [0x0x23f0e3] [UnrealEditor] : [GuardedMain(char16_t const*)] : </mnt/horde/++UE5/Sync/Engine/Source/./Runtime/Launch/Private/Launch.cpp>:60
20: [0x0x7f77727f1215] [libUnrealEditor-UnixCommonStartup.so] : [CommonUnixMain(int, char**, int (*)(char16_t const*), void (*)())] : </mnt/horde/++UE5/Sync/Engine/Source/./Runtime/Unix/UnixCommonStartup/Private/UnixCommonStartup.cpp>:323
21: [0x0x7f7765227635] [libc.so.6] : [] : <>:0
22: [0x0x7f77652276e9] [libc.so.6] : [__libc_start_main] : <>:0
23: [0x0x236e0a] [UnrealEditor] : [_start] : </opt/UE/5.7.1/Engine/Binaries/Linux/UnrealEditor>:-1