Thanks @Pascal for indicating that the drop down menu lists do appear by selecting XRender as the rendering engine.
Unfortunately XRender has other issues. The reason I originally changed away from using the default settings is because then I had issues with screen tearing [1] and an inability to login due to SDDM login screen hangs [2].
Thanks @Pascal for indicating that the drop down menu lists do appear by selecting XRender as the rendering engine.
Unfortunately XRender has other issues. The reason I originally changed away from using the default settings is because then I had issues with screen tearing [1] and an inability to login due to SDDM login screen hangs [2].
[1] https:/ /askubuntu. com/questions/ 764302/ screen- tearing- on-kubuntu- 16-04-with- intel-drivers
[2] https:/ /askubuntu. com/questions/ 765364/ kubuntu- 16-04-sddm- login-screen- hangs/