Please check the video for details. Also, i have found that there is a delay in opening the font selection dropdown.
nothing for this issue ?
Hi Arun,
Sorry for the late response 
I’m afraid that, with some variable fonts reaching a certain level of variability, Sketch encounters limitations imposed by how macOS supports variable fonts.
Could you please tell us a bit more about your use case and requirements for using a font like Roboto Flex?
We are aware of this issue, and there is room for improvement here that we must contemplate. I’m so sorry for any inconvenience this might have caused.
Its not just roboto flex font, all of my variable font behave same