There's a problem with the xserver-xorg-core-hwe-18.04 update of Jan 16 and radeon graphics cards.
There are newer versions of the package to download. More explained version of this answer in this post.
Or download the newer packages in here.
There seems to be a problem with the last update of xserver-xorg-core-hwe-18.04 or xserver-xorg-legacy-hwe-18.04 with Radeon graphics cards, which break the rendering of boxes and tooltips.
They just uploaded a fix in launchpad. Just update the packages to their newer versions
xserver-xorg-video-amdgpu-hwe-18.04:amd64 from 19.0.1-1~18.04.1 to
UPDATE I might have an actual answer / workaround: booting with kernel 5.0 (instead of 5.3) makes these issues disappear. During boot, select "Advanced options for elementary", then "elementary, with Linux 5.0.0-37-generic" (instead of the default 5.3.0-26-generic option). With this older kernel, the screen update issues do not occur for me.
By default plank is into the cerbere applications list so if you did not removed it from there, it should launch again after you kill it. I do not know why you running plank from terminal, but if you just want to restart it use killall plank instead if it is still in the cerbere list.
If you are doing this in order to change the theme, the location of the ...
This would be expected behaviour, the & whilst making it a background task does still keep it as a child process of the terminal so when the terminal is closed so does plank. If you wish to keep it alive this question may be helpful: https://unix.stackexchange.com/questions/4004/how-can-i-run-a-command-which-will-survive-terminal-close#4006.
I had the similar issue while setting up the AVD...
Here is my AVD.desktop file's current contents:
Name=Android Virtual Device
Comment=Q @ Pixel_2