Comment 17 for bug 1729433

I am experiencing this on Kubuntu 20.04.
Version: 6.4.6.2
Build ID: 1:6.4.6-0ubuntu0.20.04.1
CPU threads: 4; OS: Linux 5.4; UI render: GL; VCL: kf5;
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: CL
Operating System: Kubuntu 20.04
KDE Plasma Version: 5.18.5
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.8
Kernel Version: 5.4.0-52-generic
OS Type: 64-bit
nVidia GeForce GTX650Ti, driver 450.80.02

I have already used configure window settings - size & position -remember position / remember size
and configure application application settings - size & position -remember position / remember size.
However it keeps opening smaller than I want it to. Even manually altering the size here has no effect.

Also, dragging the window to the desired size is very slow to draw.
Opening a document also take several seconds.
This did not happen when I was using Mint KDE 17.3. Documents opened instantaneously, window remembered size, resizing fast.