I have a new version of the client available to test that is ported to use SDL2, version 2 of the Simple Direct Media layer.  There are lots of benefits from using this never version but the port has required a lot of changes. The handling of keyboard input as been totally rewritten so could do with some good testing.  One immediate change you will notice is that the client window is now resizeable and can be maximised like any normal window (needs SDL version 2.0.5 or higher).  You can also switch between full-screen and back on Windows as well as Linux without graphic glitches (this is possible because this no longer requires destroying the graphic context and hence lots of unload/reload of textures etc).   There are 32-bit and 64-bit zip packages packages for Windows.  These just contain the el.exe and dll files so save your original files before extracting into an existing install.   The snap (edge) and flatpak (develop) packages for Linux should already be using this version.  There is not yet a Linux static build as this needs major work too, but you can of course build from source.  You will need to install libsdl2-dev, libsdl2-net-dev and libsdl2-image-dev in additional to previous libraries.  I'd suggest using the CMake file.  I'll do some Ubuntu/Debian package builds ASAP.   There is also a Linux 32-bit static binary and a Linux 64-bit static binary.   The version string should show the UK date/time of the build (20191126.2321 or similar).  Please let me know how you get on with this test version.