Kwin failing to start up on login to Plasma

[testuser]

Some parts of kwin seem to not start up when I login to Plasma. Running kwin_x11 once inside solves the problem, but I would prefer to be able to login without having to run a command every time. Using AMD's new AMDGPU driver for my graphics card if it changes anything. This seems to occur on all themes.

If it matters, here is the message I get when running kwin_x11.

Spoiler:

QXcbConnection: XCB error: 3 (BadWindow), sequence: 181, resource id: 29360134, major code: 20 (GetProperty), minor code: 0
QXcbConnection: XCB error: 3 (BadWindow), sequence: 191, resource id: 29360134, major code: 20 (GetProperty), minor code: 0
QPainter::begin: Paint device returned engine == 0, type: 3
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::setWindow: Painter not active
QPainter::setClipRect: Painter not active
QPainter::save: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::setClipRect: Painter not active
QPainter::drawRects: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::drawRects: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::setFont: Painter not active
QPainter::setPen: Painter not active
QPainter::fontMetrics: Painter not active
QPainter::save: Painter not active
QPainter::translate: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::translate: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::translate: Painter not active
QPainter::scale: Painter not active
QPainter::translate: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::translate: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::translate: Painter not active
QPainter::scale: Painter not active
QPainter::translate: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::translate: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::translate: Painter not active
QPainter::scale: Painter not active
QPainter::translate: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::setBrush: Painter not active
QPainter::restore: Unbalanced save/restore
QPainter::save: Painter not active
QPainter::setRenderHint: Painter must be active to set rendering hints
QPainter::setBrush: Painter not active
QPainter::setPen: Painter not active
QPainter::drawRects: Painter not active
QPainter::restore: Unbalanced save/restore
OpenGL vendor string: X.Org
OpenGL renderer string: Gallium 0.4 on AMD HAWAII (DRM 3.3.0 / 4.8.4-server-1.mga6, LLVM 3.8.1)
OpenGL version string: 3.0 Mesa 12.0.3
OpenGL shading language version string: 1.30
Driver: Unknown
GPU class: Unknown
OpenGL version: 3.0
GLSL version: 1.30
Mesa version: 12.0.3
Linux kernel version: 4.8.4
Requires strict binding: yes
GLSL shaders: yes
Texture NPOT support: yes
Virtual Machine: no
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1941, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1951, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1952, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1953, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1955, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1957, resource id: 0, major code: 14 (GetGeometry), minor code: 0
QXcbConnection: XCB error: 9 (BadDrawable), sequence: 1958, resource id: 0, major code: 14 (GetGeometry), minor code: 0

Running Mageia 6, with kernel 4.8.4-server-1.mga6, and Plasma 8.2.

[doktor5000]

How do you start your plasma session in the first place, and what login manager do you use?