Could you try fixing this issue by upgrading to the latest beta, please? I recommend downloading and reinstalling the app from this page to unlock the latest features and bug fixes: https://icons8.com/lunacy-download
Uninstall the old version before installing the new one. Once installed, enable beta updates: Help → About → Check for Beta Updates → Install. Let me know if you are still experiencing component instance issues after the update.
Followed your instructions to the T but the issue remains. Still exporting 0.3x as 769 x 289 pixels.
btw, I see that you have added 0.1x, 0.2x and 0.3x to the size drop down. Awesome. Thank you. Could you please add 0.75x as well when you get a chance.