Nvidia added on-demand, but it not working good with external display, for example google chrome got white area rectangles instead menu with external display.

to fix it, you can use next aliases in you bashrc:

alias nvidia_run='__NV_PRIME_RENDER_OFFLOAD=1 __GLX_VENDOR_LIBRARY_NAME=nvidia __VK_LAYER_NV_optimus=NVIDIA_only'

alias intel_run='__NV_PRIME_RENDER_OFFLOAD=0 __VK_LAYER_NV_optimus=non_NVIDIA_only'